Tag Archives: IPS

Trio of Windows Bulletins Correct Moderate Vulnerabilities

Severity: Medium

Summary:

  • These vulnerabilities affect: All current versions of Windows or components often packaged with it (like the .NET Framework)
  • How an attacker exploits them: Multiple vectors of attack, including sending specially crafted network traffic or running malicious programs locally
  • Impact:  Varies, ranging from a remote Denial of Service (DoS) attack to local attackers gaining complete control of your Windows computer
  • What to do: Install the appropriate Microsoft patches as soon as possible, or let Windows Automatic Update do it for you

Exposure:

Today, Microsoft released three security bulletins that describe six vulnerabilities affecting Windows or components related to it (like the .NET Framework). They only rate these bulletins as Important, due to limited impact or mitigating factors. Each of these vulnerabilities affects different versions of Windows to varying degrees. In the worst case, a local attacker could exploit one of these flaws to gain complete control of your Windows PC. We recommend you download, test, and deploy these updates at your earliest convenience.

The summary below lists the vulnerabilities, in order from highest to lowest severity.

The HTTP Protocol Stack (HTTP.sys) is a Windows component that listens for and handles HTTP requests before passing them to a web server like IIS. It suffers from a Denial of Service (DoS) vulnerability having to do with its inability to properly handle HTTP requests with specially malformed headers. By sending a specially crafted HTTP request, a remote attacker can leverage this flaw to cause your system to stop responding. While this sort of DoS attack doesn’t result in any breach or data loss, attackers can leverage it to knock your public web server offline, which could have significant business implications. You should download, test, and deploy Microsoft’s HTTP.sys update as soon as possible.

Microsoft rating: Important

  • MS13-040Multiple .NET Framework Vulnerabilities

The .NET Framework is a software framework used by developers to create custom Windows and web applications. Though it only ships by default with Windows Vista, you’ll find it on many Windows computers. The .NET Framework component suffers from two new security vulnerabilities.

The first issue is an XML digital signature spoofing vulnerability. XML files can contain digital signatures, which .NET applications can use to verify the integrity of XML files (ensuring they haven’t been improperly modified). However, the .NET Framework component (CLR) responsible for validating these signatures doesn’t do it right. As a result, attackers can modify the contents of an XML file without invalidating the signature. The impact of this flaw depends on if and how your custom .NET applications leverage this functionality.

The second issue is an authentication bypass vulnerability. The Windows Communication Foundation (WCF) is essentially a set of .NET APIs that developers can use to make applications that communicate securely with one another. However, WCF suffers from an authentication bypass flaw. By sending specially crafted packets, an attacker could gain unauthenticated access to computers that run WCF services. The impact of this bypass depends on your custom .NET application. If you custom application gives your users access to sensitive data, then in can pose a significant risk. If you install the .NET framework, you should download, test, and install Microsoft’s update as soon as you can.

Microsoft rating: Important

  • MS13-046Kernel-Mode Driver Elevation of Privilege Flaws

The kernel is the core component of any computer operating system. Windows also ships with a kernel-mode device driver (win32k.sys), which handles the OS’s device interactions at a kernel level. The Windows kernel-mode driver suffers from three new local elevation of privilege flaws. They all differ technically, but share the same basic scope and impact. By running a specially crafted program, a local attacker could leverage this flaw to gain complete control of your Windows computers (or cause it to become unstable). However, in order to run his malicious program, the attacker would first need to gain local access to your computer or trick you into running the program yourself, which significantly lessens the severity of this vulnerability.

Microsoft rating: Important

Solution Path:

Microsoft has released Windows and .NET Framework patches that correct all of these vulnerabilities. You should download, test, and deploy the appropriate updates throughout your network immediately. If you choose, you can also let Windows Update automatically download and install them for you.

The links below point directly to the “Affected and Non-Affected Software” section of each bulletin, where you can find links to the various updates:

For All WatchGuard Users:

WatchGuard’s Gateway Antivirus and Intrusion Prevention services can often prevent some of these types of attacks, or the malware they try to distribute. For instance, our IPS signature team has developed signatures that can detect and block a few of the issues described above, including:

  • WEB Microsoft Windows 2012 Server HTTP.sys Denial of Service Vulnerability (CVE-2013-1305)
  • EXPLOIT Microsoft XML Digital Signature Spoofing Vulnerability (CVE-2013-1336)

Your XTM appliance should get this new IPS update shortly.

However, attackers can exploit some of these flaws in other ways, including by convincing users to run executable files locally. Since your gateway appliance can’t protect you against local attacks, we still recommend you install Microsoft’s updates to completely protect yourself from these flaws.

Status:

Microsoft has released patches correcting these issues.

References:

This alert was researched and written by Corey Nachreiner, CISSP (@SecAdept).


What did you think of this alert? Let us know at your.opinion.matters@watchguard.com.

Windows Updates Fix Critical RDC Flaw, and More

Severity: High

Summary:

  • These vulnerabilities affect: All current versions of Windows and some of the components that ship with it
  • How an attacker exploits them: Multiple vectors of attack, including luring users to web sites with malicious code or sending specially crafted network packets
  • Impact: In the worst case, an attacker can gain complete control of your Windows computer.
  • What to do: Install the appropriate Microsoft patches as soon as possible, or let Windows Update do it for you.

Exposure:

Today, Microsoft released six security bulletins that describe around ten vulnerabilities affecting Windows or components related to it, such as Remote Desktop Client, Active Directory, and the Antimalware client (part of Windows Defender in Windows 8). Each of these vulnerabilities affect different versions of Windows to varying degrees. A remote attacker could exploit the worst of these flaws to gain complete control of your Windows PC. We recommend you download, test, and deploy these updates – especially the critical ones – as quickly as possible.

The summary below lists the vulnerabilities, in order from highest to lowest severity.

  • MS13-029: Remote Desktop Client Code Execution Vulnerability

Remote Desktop Protocol (RDP) is a Microsoft networking protocol that allows you to view and control the desktop of one Windows computer from another networked computer. Windows ships with the Remote Desktop Client to support this functionality. According to Microsoft, an ActiveX control the Remote Desktop Client uses suffers from a “use after free” vulnerability, which remote attackers can exploit to execute arbitrary code on your system. The attacker would simply have to entice you to a web site containing malicious code to trigger the flaw. As is typical with Windows vulnerabilities, the attacker would gain your privileges, and if you’re a local administrator that means full control of your system.

Microsoft rating: Critical

  • MS13-031: Two Kernel Elevation of Privilege Vulnerabilities

The kernel is the core component of any computer operating system. The Windows kernel suffers from two race condition vulnerabilities, which attackers can leverage to  elevate their privilege. Though the flaws differ technically, the share the same scope and impact. By running a specially crafted program, a local attacker could exploit this flaw to gain complete control of your PC. However, the attacker would first need to gain local access to your Windows computer using valid credentials. This factor significantly reduces the severity of the issue

Microsoft rating: Important

  • MS13-032: Active Directory Memory Consumption Flaw

Active Directory (AD) provides central authentication and authorization services for Windows computers and ships with server versions of Windows. AD suffers from a memory consumption vulnerability having to do with it’s inability to properly handle specially crafted LDAP queries. By sending a malicious LDAP query to an AD server, an attacker can exploit this flaw to force the server’s LDAP service to stop responding, putting it into a Denial of Service (DoS) state. However, administrators typically limit LDAP access to their local network, so this vulnerability primarily poses an internal threat.

Microsoft rating: Important

  • MS13-033CSRSS Elevation of Privilege Vulnerability

The Client/Server Run-time SubSystem (CSRSS) is an essential Windows component responsible for console windows and creating and deleting threads. It suffers from a local privilege elevation issue. By running a specially crafted application, an attacker can leverage this flaw to execute code with full system privileges, regardless of his actual user privilege. However, in order to run his special program, the attacker would first need to gain local access to your Windows computers using valid credentials. This factor significantly reduces the risk of this flaw.

Microsoft rating: Important

  • MS13-034: Antimalware Client Elevation of Privilege Vulnerability

The Antimalware Client is a free host-based security program that does just what you’d expect; protects Windows systems from malicious software (viruses, worms, trojans, etc.) loosely known as malware. It ships with Windows Defender, which comes with Windows 8. It also suffers from a local privilege elevation issue having to do with its inability to handle improper pathnames. By running a specially crafted application, an attacker can leverage this flaw to execute code with full system privileges, regardless of his actual user privilege. However, in order to run his special program, the attacker would first need to gain local access to your Windows computers using valid credentials, which significantly reduces the risk of this flaw. This issue primarily affects Windows 8 computers.

Microsoft rating: Important

  • MS13-036Multiple Kernel-Mode Driver Vulnerabilities

As mentioned above, the kernel is the core component of any computer operating system. Windows also ships with a kernel-mode device driver (win32k.sys), which handles the OS’s device interactions at a kernel level. The Windows kernel-mode driver suffers five different privilege elevation vulnerabilities. The vulnerabilities differ technically  but share the same scope and impact. By running a specially crafted program, a local attacker can leverage any of these flaws to gain complete control of your Windows computers. However, in order to run his malicious program, the attacker would first need to gain local access to your computer or trick you into running the program yourself, which significantly lessens the severity of these issues.

Microsoft rating: Important

Solution Path:

Microsoft has released Windows updates that correct all of these vulnerabilities. You should download, test, and deploy the appropriate updates throughout your network immediately. If you choose, you can also let Windows Update automatically download and install them for you.

The links below point directly to the “Affected and Non-Affected Software” section of each bulletin, where you can find links to the various updates:

For All WatchGuard Users:

WatchGuard’s Gateway Antivirus and Intrusion Prevention services can often prevent these sorts of attacks, or the malware they try to distribute. For instance, our IPS signature team has developed a new signature that can detect and block the Remote Desktop Client vulnerability described above:

  • WEB-ACTIVEX Microsoft RDC ActiveX Control Remote Code Execution Vulnerability (CVE-2013-1296)

Your XTM appliance should get this new IPS update shortly.

Nonetheless, attackers can exploit some of these flaws in other ways, including by convincing users to run executable files locally. Since your gateway appliance can’t protect you against local attacks, we still recommend you install Microsoft’s updates to completely protect yourself from these flaws.

Status:

Microsoft has released patches correcting these issues.

References:

This alert was researched and written by Corey Nachreiner, CISSP (@SecAdept).


What did you think of this alert? Let us know at your.opinion.matters@watchguard.com.

Windows Updates Fix a Wide Range of Security Vulnerabilities

Severity: High

Summary:

  • These vulnerabilities affect: All current versions of Windows and some of the components that ship with it (such as DirectShow and the .NET Framework)
  • How an attacker exploits them: Multiple vectors of attack, including sending specially crafted packets, luring users to view malicious media or email, and so on
  • Impact: In the worst case, an attacker can gain complete control of your Windows computer.
  • What to do: Install the appropriate Microsoft patches as soon as possible, or let Windows Automatic Update do it for you.

Exposure:

Today, Microsoft released eight security bulletins that describe around 39 vulnerabilities affecting Windows or components related to it, such as the .NET Framework and DirectShow. Each of these vulnerabilities affects different versions of Windows to varying degrees.

A remote attacker could exploit the worst of these flaws to gain complete control of your Windows PC. We recommend you download, test, and deploy these updates – especially the critical ones – as quickly as possible.

The summary below lists the vulnerabilities, in order from highest to lowest severity.

  • MS13-011: DirectShow Media Decompression Vulnerability

DirectShow (code-named Quartz) is a multimedia component that helps Windows handle various media streams and files. It suffers from an unspecified vulnerability having to do with how it handles specially crafted media. By getting your users to interact with malicious media, an attacker could leverage this flaw to execute code on that user’s computer, with the user’s privileges. Attackers might lure users to their booby-trapped media by linking it as a direct download, embedding it in a document, or by hosting it as a malicious media stream.

Microsoft rating: Critical

  • MS13-020: Windows XP OLE Automation Vulnerability

Object Linking and Embedding (OLE) Automation is a Microsoft protocol which allows one application to share data with, or control, another application. It suffers from an unspecified remote code execution flaw having to do with how it parses maliciously crafted  RTF files. If an attacker can convince you to open or preview a specially crafted RTF file in Windows, he could exploit this flaw to execute code on your machine, with your privileges.  If you have administrative rights, the attacker would gain complete control of your computer. This flaw only affects Windows XP.

Microsoft rating: Critical

  • MS13-014: NFS Server DoS Vulnerability

Network File System (NFS) is an industry-wide protocol for sharing files and directories over a network. Windows Server software ships with NFS support to share files in mixed, Unix and Windows environments.

Windows’ NFS service suffers from something called a null dereference vulnerability, which attackers can leverage to cause a Denial of Service (DoS) condition on Windows servers. By attempting to rename a file or folder on a read-only share, an attacker could exploit this flaw to cause the server to stop responding or crash. However, a few factors mitigate the severity of this issue. Specifically, the flaw only affects servers with the NFS role enabled; the attacker needs access to an NFS share and legitimate credentials; and finally, most administrators don’t allow NFS access through their firewall.

Microsoft rating: Important

  • MS13-015: .NET Framework EoP Vulnerability

The .NET Framework is a software framework used by developers to create custom Windows and web applications. Though it only ships by default with Windows Vista, you’ll find it on many Windows computers.

The .NET Framework suffers from a technically complex elevation of privilege (EoP) vulnerability, where it unnecessarily elevates the permissions of a callback function when a .NET application creates a particular object. If an attacker can entice a user who’s installed the .NET Framework to a specially crafted web site, he can exploit this flaw to execute code on that user’s computer with full system privileges. This flaw also can affect non-web .NET applications, which an attacker runs directly on a system. The good news is most versions of IE will either block or warn you about the particular web content (XBAP) attackers use to leverage this flaw, which significantly mitigates its risk.

Microsoft rating: Important

  • MS13-016: Multiple Kernel-Mode Driver Vulnerabilities

The kernel is the core component of any computer operating system. Windows also ships with a kernel-mode device driver (win32k.sys), which handles the OS’s device interactions at a kernel level. The Windows kernel-mode driver suffers 30 race condition vulnerabilities. The vulnerabilities differ technically  but share the same scope and impact. By running a specially crafted program, a local attacker can leverage any of these flaws to gain complete control of your Windows computers. However, in order to run his malicious program, the attacker would first need to gain local access to your computer or trick you into running the program yourself, which significantly lessens the severity of these issues.

Microsoft rating: Important

  • MS13-017 Kernel Elevation of Privilege Vulnerability

As mentioned above, the kernel is the core component of any computer operating system. The Windows kernel suffers from three vulnerabilities (two race conditions), which attackers can leverage to  elevate their privilege. By running a specially crafted program, a local attacker could exploit this flaw to gain complete control of your PC. However, the attacker would first need to gain local access to your Windows computer using valid credentials.

Microsoft rating: Important

  • MS13-018: Windows TCP/IP Stack  DoS Vulnerability

As you would expect, the Windows TCP/IP stack is a set of networking protocols that allows your computer to get on the Internet and participate in modern networking. Unfortunately, the Windows TCP/IP stack suffers from a DoS vulnerability involving the way it parses specially crafted packets.  In short, an attacker can lock or crash a Windows computer simply by sending it a sequence of specially crafted packets. Though Microsoft only rates this update as Important, attackers could repeatedly exploit it against your public Windows server, essentially knocking them offline. This could have serious implications for essential production servers. We recommend you test and apply this update immediately.

Microsoft rating: Important

  • MS13-019CSRSS Elevation of Privilege Vulnerability

The Client/Server Run-time SubSystem (CSRSS) is an essential Windows component responsible for console windows and creating and deleting threads. It suffers from a local privilege elevation issue. By running a specially crafted application, an attacker can leverage this flaw to execute code with full system privileges, regardless of his actual user privilege. However, in order to run his special program, the attacker would first need to gain local access to your Windows computers using valid credentials. This factor significantly reduces the risk of this flaw.

Microsoft rating: Important

Solution Path:

Microsoft has released Windows, DirectShow (quartz.dll), and .NET Framework patches that correct all of these vulnerabilities. You should download, test, and deploy the appropriate updates throughout your network immediately. If you choose, you can also let Windows Update automatically download and install them for you.

The links below point directly to the “Affected and Non-Affected Software” section of each bulletin, where you can find links to the various updates:

For All WatchGuard Users:

WatchGuard’s Gateway Antivirus and Intrusion Prevention services can often prevent these sorts of attacks, or the malware they try to distribute.

More specifically, our IPS signature team has developed new signatures that can detect and block the DirectShow Media Decompression and OLE Automation vulnerabilities. Your XTM appliance should get this new IPS update shortly.

Nonetheless, attackers can exploit some of these flaws in other ways, including by convincing users to run executable files locally. Since your gateway appliance can’t protect you against local attacks, we still recommend you install Microsoft’s updates to completely protect yourself from these flaws.

Status:

Microsoft has released patches correcting these issues.

References:

This alert was researched and written by Corey Nachreiner, CISSP (@SecAdept).


What did you think of this alert? Let us know at your.opinion.matters@watchguard.com.

Two IE Bulletins Double the Browser Updates

Severity: High

Summary:

  • These vulnerabilities affect: Internet Explorer (IE) 10 and earlier
  • How an attacker exploits them: Typically, by enticing one of your users to visit a web page with malicious content
  • Impact: Various; In the worst case, an attacker can execute code on your user’s computer, often gaining complete control of it
  • What to do: Install Microsoft’s Internet Explorer updates immediately, or let Windows Automatic Update do it for you

Exposure:

In a relatively unusual move, Microsoft released two Internet Explorer (IE) security bulletins today, rather than their typical single cumulative update. Combined, the two bulletins fix 14 vulnerabilities in the popular web browser, many of which allow attackers to execute code on vulnerable Windows systems.

We summarize the two bulletins below:

  • MS13-009: February IE Cumulative Update

This update fixes 13 vulnerabilities in IE, most of them being  “use after free” vulnerabilities similar to the ones Microsoft fixed with last month’s out-0f-cycle IE bulletin.  By luring one of your users to a web site containing malicious code, a remote attacker can exploit most of these vulnerabilities to execute code on your computer, with your privileges.  As always, if you have local administrator privileges, the attacker could exploit this issue to gain complete control of your computer.

Microsoft rating: Critical

  • MS13-010: VML Memory Corruption Vulnerability

Vector Markup Language (VML) is a graphics standard for creating 2D vector illustrations with XML files. The VML component in IE suffers from a memory corruption vulnerability having to do with how it allocates buffers. By enticing your users to a web site with specially crafted content, a remote attacker could exploit this flaw to execute code on that user’s computer, with the user’s privileges. Since most Windows users have local administrative privileges, this sort of attack often gives the attacker complete control of their computers.

Microsoft rating: Critical

Malicious hackers often leverage these types of vulnerabilities in drive-by download attacks, and they also target legitimate web sites and booby-trap them with malicious code. In other words, you can sometimes encounter these sorts of “drive-by download” attacks even while visiting trusted, legitimate web sites. We recommend you update your IE users immediately.

Solution Path:

These updates fix serious issues. You should download, test, and deploy the appropriate IE patches immediately, or let Windows Automatic Update do it for you.

The links below point directly to the “Affected and Non-Affected Software” section of each bulletin, where you can find links to the various updates:

For All WatchGuard Users:

These attacks travel as normal-looking HTTP traffic, which you must allow if your network users need to access the World Wide Web. Therefore, the patches above are your best solution.

That said, WatchGuard’s Gateway Antivirus and Intrusion Prevention Service can often prevent these sorts of attacks, or the malware they try to distribute. For instance, our IPS team has created signatures for  the following:

  • Various “use after free” vulnerabilities - CVE-2013-0018, CVE-2013-0019, CVE-2013-0020, CVE-2013-0021, CVE-2013-0022, CVE-2013-0023, CVE-2013-0024, CVE-2013-0025, CVE-2013-0026, CVE-2013-0027, CVE-2013-0028, CVE-2013-0029
  • JIS character encoding vulnerability - CVE-2013-0015
  • VML memory corruption vulnerability - CVE-2013-0030

These signatures will be available in our next IPS update, which should come out shortly. We highly recommend you enable our security services on your WatchGuard XTM and XCS appliances, and keep IPS and AV up to date.

Status:

Microsoft has released patches to fix these vulnerabilities.

References:

This alert was researched and written by Corey Nachreiner, CISSP (@SecAdept).

Microsoft Piles on Patches Next Tuesday

February looks to be a busy month for Microsoft administrators. According to the latest advanced patch notification, the Redmond-based software company plans to release a dozen security bulletins next Tuesday. The bulletins will fix security flaws in Windows, Internet Explorer (IE), Office, the .NET Framework, and Exchange server. Microsoft rates five of the  bulletins as Critical, and the rest as Important.

In the middle of last month, Microsoft released an out-of-cycle IE update to fix a flaw attackers were leveraging in the wild. It appears that update didn’t fix everything in IE since at least two of the upcoming bulletins affect the popular web browser.

As always, we’ll share more about these updates, and the vulnerabilities they correct, next week. You can also expect our IPS signature team to have signatures prepared for any known exploits that Microsoft shares with us. In the meantime, prepare your IT team for a pretty full plate of patches. — Corey Nachreiner, CISSP (@SecAdept)

Microsoft Patch Day: Feb. 2013

Windows Updates Include .NET and MSXML Fixes

Severity: High

Summary:

  • These vulnerabilities affect: All current versions of Windows and components that often ship with it (like XML Core Services and the .NET Framework). Some vulnerable components also affect Office and Server Software products.
  • How an attacker exploits them: Multiple vectors of attack, including sending malicious print jobs to luring victims to malicious web pages.
  • Impact: In the worst case, an attacker can gain complete control of your Windows computer.
  • What to do: Install the appropriate Microsoft patches as soon as possible, or let Windows Automatic Update do it for you.

Exposure:

Today, Microsoft released six security bulletins that describe 11 vulnerabilities affecting Windows or components related to it,  such as the .NET Framework and XML Core Services (MSXML). Each of these vulnerabilities affects different versions of Windows to varying degrees. One of the component vulnerabilities (MSXML) also affects other Microsoft products, including Office, SharePoint Server, and Microsoft Expression.

A remote attacker could exploit the worst of these flaws to gain complete control of your Windows PC. We recommend you download, test, and deploy these updates – especially the critical ones – as quickly as possible.

The summary below lists the vulnerabilities, in order from highest to lowest severity.

  • MS13-001: Print Spooler Remote Code Execution Vulnerability

The print spooler is a Windows service that manages printing. It suffers from an unspecified vulnerability having to do with its inability to handle specially crafted print jobs. By sending a specially crafted print request, an attacker can exploit this flaw to execute code on a Windows computer with full system privileges.  That said, most administrators do not allow the ports necessary for Windows printing through their firewall. By default, a WatchGuard XTM appliance will block Internet-based attackers from leveraging this flaw, so it primarily poses an internal threat.

Microsoft rating: Critical

  • MS13-002: Two MSXML Remote Code Execution Flaws

Microsoft XML Core Services (MSXML)  is a component that helps Windows, Internet Explorer, and other Microsoft products handle XML content. It often ships with various versions of Windows, and other Microsoft products like Office, SharePoint Server, Groove Server, and Expressions. If you have a Windows computer, you very likely have MSXML, and you need to update if you use any of the aforementioned products.

According to today’s bulletin, MSXML suffers from two vulnerabilities – likely memory corruption flaws, but Microsoft doesn’t specify – which remote attackers could leverage to execute code on vulnerable computers with the privileges of the currently logged-in user. An attacker would only have to lure you to a web site containing malicious XML content for his attack to succeed. Since most Windows users have local administrative privileges, this sort of attack often gives the attacker complete control of their computers.

Don’t forget, attackers often booby-trap legitimate web sites with drive-by download code. So it’s possible you could encounter attacks leveraging this sort of vulnerability when visiting perfectly legitimate web sites. We recommend you patch quickly to avoid these sorts of attacks.

Microsoft rating: Critical

  • MS13-004Multiple .NET Framework Vulnerabilities

The .NET Framework is a software framework used by developers to create custom Windows and web applications. Though it only ships by default with Windows Vista, you’ll find it on many Windows computers.

The .NET Framework component suffers from four new security vulnerabilities.  The flaws differ in scope and impact, and include an information disclosure issue, and three elevation of privilege vulnerabilities; two due to buffer overflow flaws. If an attacker can entice a user who’s installed the .NET Framework to a specially crafted web site, he can exploit the worst of these flaws to execute code on that user’s computer with full system privileges. This flaw also can affect non-web .NET applications, including custom ones you may have developed in-house. In short, if you’ve installed the .NET framework on any of your servers or clients, you should update them as quickly as possible.

Microsoft rating: Important

  • MS13-005Kernel-Mode Driver Elevation of Privilege Flaw

The kernel is the core component of any computer operating system. Windows also ships with a kernel-mode device driver (win32k.sys), which handles the OS’s device interactions at a kernel level. The Windows kernel-mode driver suffers from a new local elevation of privilege flaw having to do with how it improperly handles window broadcast messages. By running a specially crafted program, a local attacker could leverage this flaw to gain complete control of your Windows computers. However, in order to run his malicious program, the attacker would first need to gain local access to your computer or trick you into running the program yourself, which significantly lessens the severity of this vulnerability.

Microsoft rating: Important

  • MS13-006: Windows SSLv3/TLS Degradation Attack

The Secure Socket Layer and Transport Layer Security (SSL/TLS) protocols are responsible for helping computers establish secure connection over networks. For instance, SSL/TLS is what you use when connecting to secure web sites. Like all operating systems, Windows ships with components necessary to handle SSL/TLS connections.

According to Microsoft’s bulletin, the SSL/TLS implementation that ships with most versions of Windows suffers from what they call a “Security Feature Bypass vulnerability.” Windows supports SSLv3, which includes the latest encryption ciphers. However, if an attacker can perform a Man-in-the-Middle attack on your SSL traffic, he can inject maliciously crafted traffic that forces Windows to downgrade to SSLv2. This doesn’t give the attacker immediate access to the SSL encrypted traffic, but it theoretically makes it easier to crack the SSL encryption, since SSLv2 supports weaker ciphers. Since this attack is relatively difficult to carry out, and doesn’t result in any true decryption of the SSL communication, we believe it poses a relatively low risk in the real world. Of course, we still recommend you patch it.

Microsoft rating: Important

At the highest level, the Open Data (OData) protocol is a standard that web applications can use to query and update data. In short, it’s like the many other protocols developers might use to get a web application to interact with a database. The OData component that ships with the .NET Framework suffers from a Denial of Service (DoS) vulnerability. By sending specially crafted HTTP requests, an attacker can leverage this flaw to disrupt your web server, preventing visitors from accessing it. Any IIS web server that includes the .NET Framework and has the Windows Communication Foundation (WCF) services installed is vulnerable to this DoS flaw, as is any Windows Server 2012 with IIS and the Management OData IIS Extension installed.

Microsoft rating: Important

Solution Path:

Microsoft has released Windows, .NET Framework, and XML Core Services patches that correct all of these vulnerabilities. You should download, test, and deploy the appropriate updates throughout your network immediately. If you choose, you can also let Windows Update automatically download and install them for you.

The links below point directly to the “Affected and Non-Affected Software” section of each bulletin, where you can find links to the various updates:

For All WatchGuard Users:

WatchGuard’s Gateway Antivirus and Intrusion Prevention services can often prevent these sorts of attacks, or the malware they try to distribute.

More specifically, our IPS signature team has developed a new signature that can detect and block the OData DoS vulnerability against IIS servers with the .NET Framework. Your XTM appliance should get this new IPS update shortly.

Nonetheless, attackers can exploit some of these flaws in other ways, including by convincing users to run executable files locally. Since your gateway appliance can’t protect you against local attacks, we still recommend you install Microsoft’s updates to completely protect yourself from these flaws.

Status:

Microsoft has released patches correcting these issues.

References:

This alert was researched and written by Corey Nachreiner, CISSP (@SecAdept).


What did you think of this alert? Let us know at your.opinion.matters@watchguard.com.

Malformed Fonts and Filenames Mangle Windows

Severity: High

Summary:

  • These vulnerabilities affect: All current versions of Windows
  • How an attacker exploits them: Multiple vectors of attack, including enticing users to view maliciously crafted fonts or to view directories with specially crafted files or folder names
  • Impact: In the worst case, an attacker can gain complete control of your Windows computer
  • What to do: Install the appropriate Microsoft patches as soon as possible, or let Windows Automatic Update do it for you.

Exposure:

Today, Microsoft released four security bulletins describing five vulnerabilities that affect Windows. Each vulnerability affects different versions of Windows to varying degrees. However, a remote attacker could exploit the worst of these flaws to gain complete control of your Windows PC. We recommend you download, test, and deploy these updates – especially the critical ones – as quickly as possible.

The summary below lists the vulnerabilities, in order from highest to lowest severity.

  • MS12-078: Two Windows Font Handling Vulnerabilities

The kernel is the core component of any computer operating system. Windows also ships with a kernel-mode device driver (win32k.sys), which handles the OS’s device interactions at a kernel level, and plays a part in font handling. This kernel-mode driver suffers from two remote code execution vulnerabilities involving the way it handles TrueType (TTF) and OpenType (OTF) fonts. By enticing one of your users to view a specially crafted font, perhaps hosted at a malicious web site, an attacker could leverage either of these flaws to gain complete, kernel-level, control of your computer. These are extremely risky issues as you simply have to view something with an evil font to trigger them.

Microsoft rating: Critical

  • MS12-081: Windows Filename Parsing Flaw

Windows suffers from an unspecified vulnerability involving the way it parses specially malformed filenames or folders names. If an attacker can place a specially crafted file or folder onto your computer, or one of the shares you access, and she can lure you into viewing (not opening) that file or folder, she can exploit this flaw to execute code with your privileges. If you have local administrator privileges, the attacker would gain full control of Windows.

Microsoft rating: Critical

  • MS12-082 :  DirectPlay Buffer Overflow Vulnerability

DirectX is a multimedia development API, primarily used by programmers to make games for Windows and to handle multimedia. It includes DirectPlay, a DirectX networking protocol specifically used to create networked, multi-player games. DirectPlay suffers from a heap buffer overflow vulnerability involving its inability to properly handle specially formed office documents. By enticing you to open an office document with malicious embedded content, an attacker can exploit this flaw to execute code on your system, with your privileges. Like always, if you are a local administrator it’s game over. This attack requires some user interaction, which somewhat mitigates its severity.

Microsoft rating: Important

  • MS12-083 :  IP-HTTPS Certificate Bypass Vulnerability

DirectAccess is a Microsoft conceived, VPN-like feature that allows you to securely access your organization’s internal, private networks. It uses something called IP over HTTPS (IP-HTTPS)  to create these secure connections. IP-HTTPS doesn’t properly check the validity of certificates. Specifically, it doesn’t recognize revoked certificates. If an attacker has access to one of your revoked certificates, he can use it to bypass the security of DirectAccess.

Microsoft rating: Important

Solution Path:

Microsoft has released Windows patches that correct all of these vulnerabilities. You should download, test, and deploy the appropriate Windows patches throughout your network immediately. If you choose, you can also let Windows Update automatically download and install these updates for you.

The links below point directly to the “Affected and Non-Affected Software” section of each bulletin, where you can find the various updates:

For All WatchGuard Users:

WatchGuard’s Gateway Antivirus and Intrusion Prevention services can often prevent these sorts of attacks, or the malware they try to distribute.

More specifically, our IPS signature team has developed new signatures, which can detect and block many of these new Windows-related vulnerabilities:

  • EXPLOIT Microsoft Open Type Font Parsing Vulnerability (CVE-2012-2556)
  • EXPLOIT Microsoft Windows Filename Parsing Vulnerability (CVE-2012-4774)

Your appliance should get this new IPS update shortly.

Nonetheless, attackers can exploit some of these flaws in other ways. We still recommend you install Microsoft’s updates to completely protect yourself from these flaws.

Status:

Microsoft has released patches correcting these issues.

References:

This alert was researched and written by Corey Nachreiner, CISSP (@SecAdept).


What did you think of this alert? Let us know at your.opinion.matters@watchguard.com.

Nasty RTFs Nudge Word Into Submission

Severity: High

Summary:

  • These vulnerabilities affect: Word (and Office) 2003 through 2010 for Windows (and related components)
  • How an attacker exploits it: By enticing one of your users to open a malicious RTF document
  • Impact: In the worst case, an attacker executes code on your user’s computer, gaining complete control of it
  • What to do: Install Microsoft’s Word update as soon as possible, or let Microsoft’s automatic update do it for you

Exposure:

As part of today’s Patch Day, Microsoft released a security bulletin describing a serious security vulnerability in the Windows version of Word — part of Microsoft Office package. The flaw doesn’t affect the Mac versions, but does affect the Word viewer and Office Compatibility Packs.

The vulnerability stems from an unspecified memory corruption fkaw having to do with how Word handles rich text format (RTF) documents. If an attacker can entice one of your users into downloading and opening a maliciously crafted RTF document, he can exploit the flaw to execute code on that user’s computer, usually inheriting that user’s level of privileges and permissions. If your user has local administrative privileges, the attacker gains full control of the user’s machine.

Solution Path

Microsoft has released Word and Office updates to correct these vulnerabilities. If you use Office or Word, download, test, and deploy the appropriate updates as quickly as possible, or let Windows Update do it for you.

You’ll find links to these updates in the “Affected and Non-Affected Software” section for of Microsoft’s Word bulletin.

For All WatchGuard Users:

WatchGuard’s Gateway Antivirus and Intrusion Prevention services can often prevent these sorts of attacks, or the malware they try to distribute.

More specifically, our IPS signature team has developed a signature, which detects and blocks this Word RTF vulnerability:

  • EXPLOIT Microsoft Word RTF listoverridecount Remote Code Execution Vulnerability (CVE-2012-2539)

Your appliance should get this new IPS update shortly.

You can also configure WatchGuard devices to block RTF documents. However, this will block all RTFs, whether legitimate or malicious. If you decide you want to block them, the links below contain instructions that will help you configure proxy’s content blocking features for your device:

Status:

Microsoft has released Word updates to fix these vulnerabilities.

References:

This alert was researched and written by Corey Nachreiner, CISSP.

Four Critical Spreadsheet Handling Flaws in Excel

Severity: Medium

Summary:

  • These vulnerabilities affect: Excel (and Office) 2003 through 2010 for Mac and PC (and related components)
  • How an attacker exploits it: By enticing one of your users to open a malicious Excel document
  • Impact: In the worst case, an attacker executes code on your user’s computer, gaining complete control of it
  • What to do: Install Microsoft’s Excel updates as soon as possible, or let Microsoft’s automatic update do it for you

Exposure:

As part of today’s Patch Day, Microsoft released a security bulletin describing four vulnerabilities found in Excel — part of Microsoft Office for Windows and Mac. The flaws also affect the Excel viewer and Office Compatibility Package.

Though the four vulnerabilities differ technically, they are all memory corruption issues which share the same scope and impact. If an attacker can entice one of your users into downloading and opening a maliciously crafted Excel document, he can exploit any of these vulnerabilities to execute code on a victim’s computer, usually inheriting that user’s level of privileges and permissions. If your user has local administrative privileges, the attacker gains full control of the user’s machine.

Solution Path

Microsoft has released Excel and Office updates to correct these vulnerabilities. If you use Office or Excel on a PC or Mac, download, test, and deploy the appropriate updates as quickly as possible, or let Windows Update do it for you.

You’ll find links to these updates in the “Affected and Non-Affected Software” section for of Microsoft’s Excel security bulletin.

For All WatchGuard Users:

WatchGuard’s Gateway Antivirus and Intrusion Prevention services can often prevent these sorts of attacks, or the malware they try to distribute.

More specifically, our IPS signature team has developed four signatures, which can detect and block these new Excel file handling vulnerabilities:

  • EXPLOIT Microsoft Excel SST Invalid Length Use After Free Vulnerability (CVE-2012-1887)
  • EXPLOIT Microsoft Excel Memory Corruption Vulnerability (CVE-2012-1886)
  • EXPLOIT Microsoft Excel SerAuxErrBar Heap Overflow Vulnerability (CVE-2012-1885)
  • EXPLOIT Microsoft Excel Stack Overflow Vulnerability (CVE-2012-2543)

Your appliance should get this new IPS update shortly.

You can also configure certain WatchGuard devices to block Microsoft Excel documents. However, this will block all Excel documents, whether legitimate or malicious. If you decide you want to block Excel files, the links below contain instructions that will help you configure proxy’s content blocking features for your device:

Status:

Microsoft has released Excel updates to fix these vulnerabilities.

References:

This alert was researched and written by Corey Nachreiner, CISSP.

Three Critical Windows and .NET Bulletins

Severity: High

Summary:

  • These vulnerabilities affect: All current versions of Windows and the .NET Framework
  • How an attacker exploits them: Multiple vectors of attack, including enticing users to view malicious fonts or to open specially crafted Briefcase folders
  • Impact: In the worst case, an attacker can gain complete control of your Windows computer
  • What to do: Install the appropriate Microsoft patches as soon as possible, or let Windows Automatic Update do it for you.

Exposure:

Today, Microsoft released three security bulletins describing ten vulnerabilities that affect Windows and components that often ship with it, such as the .NET Framework. Each vulnerability affects different versions of Windows to varying degrees. However, a remote attacker could exploit the worst of these flaws to gain complete control of your Windows PC. We recommend you download, test, and deploy these updates – especially the critical ones – as quickly as possible.

The summary below lists the vulnerabilities, in order from highest to lowest severity.

  • MS12-072: Two Windows Briefcase Memory Corruption Flaws

Briefcase is a Windows feature that allows you to keep files on two computers in sync, by placing them in a special “briefcase” folder. Unfortunately, Briefcase suffers from two memory corruptions flaws; an integer overflow and underflow vulnerability. By enticing one of your users to a maliciously crafted Briefcase folder, an attacker could exploit this flaw to execute code on that user’s computer, with that user’s level of privilege. Since most Windows users have local administrative rights, this typically means the attacker gains complete control of the victim computer.

Microsoft rating: Critical

  • MS12-074: Multiple .NET Framework Vulnerabilities

The .NET Framework is a software framework used by developers to create new Windows and web applications. Though it only ships by default with Windows Vista, you’ll find it on many Windows computers since it is essential to many applications.

The .NET Framework component suffers from five new security vulnerabilities.  The flaws differ greatly in scope and impact, and include an information disclosure issue, some elevation of privilege flaws, and a few remote code execution vulnerabilities. If an attacker has access to your local network, and can perform an ARP poisoning attack, he can exploit one of the worst vulnerabilities (in WPAD) to execute code on your Windows computers, with the local user’s privileges. If the user has local administrator privileges, the attacker gains full control of the computer. In short, if you install the .NET Framework on your Windows computers, you should update it as soon as possible.

Microsoft rating: Critical

  • MS12-075 :  Kernel-Mode Driver Elevation of Privilege Flaw

The kernel is the core component of any computer operating system. Windows also ships with a kernel-mode device driver (win32k.sys), which handles the OS’s device interactions at a kernel level. The Windows kernel-mode driver suffers from two elevation of privilege flaws and a remote code execution flaw. By enticing one of your users to view a specially crafted font, perhaps hosted at a malicious web site, an attacker could leverage the worst of these flaws to gain complete, kernel-level, control of your computer.

Microsoft rating: Critical

Solution Path:

Microsoft has released Windows patches that correct all of these vulnerabilities. You should download, test, and deploy the appropriate Windows patches throughout your network immediately. If you choose, you can also let Windows Update automatically download and install these updates for you.

The links below point directly to the “Affected and Non-Affected Software” section of each bulletin, where you can find the various updates:

For All WatchGuard Users:

WatchGuard’s Gateway Antivirus and Intrusion Prevention services can often prevent these sorts of attacks, or the malware they try to distribute.

More specifically, our IPS signature team has developed new signatures, which can detect and block many of these new Windows-related vulnerabilities:

  • EXPLOIT Microsoft Web Proxy Auto-Discovery Vulnerability (CVE-2012-4776)
  • EXPLOIT .NET Framework Insecure Library Loading -1 (CVE-2012-2519)
  • EXPLOIT .NET Framework Insecure Library Loading -2 (CVE-2012-2519)
  • EXPLOIT Windows Font Parsing Vulnerability (CVE-2012-2897)
  • EXPLOIT Microsoft Windows Briefcase Integer Underflow Vulnerability (CVE-2012-1527)
  • EXPLOIT Microsoft Windows Briefcase Integer Overflow Vulnerability (CVE-2012-1528)

Your appliance should get this new IPS update shortly.

Nonetheless, attackers can exploit some of these flaws in other ways, including by convincing users to run executable files locally. Since your gateway appliance can’t protect you against local attacks, we still recommend you install Microsoft’s updates to completely protect yourself from these flaws.

Status:

Microsoft has released patches correcting these issues.

References:

This alert was researched and written by Corey Nachreiner, CISSP (@SecAdept).


What did you think of this alert? Let us know at your.opinion.matters@watchguard.com.

Follow

Get every new post delivered to your Inbox.

Join 7,389 other followers

%d bloggers like this: