Tag Archives: TCP/IP

Windows Updates Mend Critical Journal Vulnerability & More

Severity: High

Summary:

  • These vulnerabilities affect: All current versions of Windows (and related components like XML Core Services)
  • How an attacker exploits them: Multiple vectors of attack, including enticing you to malicious web sites, or into interacting with malicious documents or images.
  • 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 in Windows and related components, such as XML Core Services. An attacker could exploit the worst of these flaws to potentially gain complete control of your Windows PC. We recommend you download, test, and deploy these critical updates as quickly as possible.

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

Windows Journal is a basic note taking program that ships with Windows systems (though the server versions of Windows do not install it by default). It suffers from a vulnerability involving how it  handles specially crafted Journal files (.JNT). If an attacker can trick you into opening a malicious Journal file, perhaps embedded in an email or web site, he can exploit this flaw to execute code on your computer, with your privileges. If you have local administrative privileges, the attacker gains full control of your computer.

Microsoft rating: Critical

  • MS14-039:  On-Screen Keyboard Privilege Elevation Vulnerability

Windows ships with an accessibility option called the On-Screen Keyboard (OSK), which displays a virtual keyboard on your display you can use for character entry. It suffers from a local elevation of privilege (EoP) vulnerability. Basically, low privileged processes can run the OSK and use it to run other programs with the logged in users privileges. However, to exploit this flaw an attacker would first have to exploit another vulnerability in a low integrity process, which lessens the severity of this issue.

Microsoft rating: Important

  • MS14-040:  AFD Privilege Elevation Vulnerability

The Ancillary Function Driver (AFD) is a Windows component that helps manage Winsock TCP/IP communications. It suffers from a local elevation of privilege (EoP) 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

  • MS14-041:  DirectShow Privilege Elevation Vulnerability

DirectShow (code-named Quartz) is a multimedia component that helps Windows handle various media streams, images, and files. It suffers from a local elevation of privilege (EoP) vulnerability. If an attacker can exploit another vulnerability to gain access to a low integrity process, she could then exploit this flaw this flaw to elevate her privileges to that of the currently logged in user.

Microsoft rating: Important

Microsoft’s Patch Day Video Summary:

Microsoft has recently started producing short videos to summarize each month’s Patch Day, which I’ve linked here for your convenience.

(Runtime: 2:24)

Direct YouTube Link: https://www.youtube.com/watch?v=3j-5-xIMgks

Solution Path:

Microsoft has released various 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. As always, you should test your updates before deploying them.

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 XTM appliances offer defenses that can mitigate the risk of some of these flaws; especially the Critical Windows Journal vulnerability. If you choose, you can leverage our proxies to prevent your users from receiving Journal files (.JNT) via email, web sites, or FTP sites. However, attackers can exploit some of the other flaws locally. Since your gateway XTM appliance can’t protect you against local attacks, we recommend you install Microsoft’s updates to completely protect yourself.

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 GDI+, RDP, and TCP Vulnerabilities

Severity: High

Summary:

  • These vulnerabilities affect: All current versions of Windows (and related components like XML Core Services)
  • How an attacker exploits them: Multiple vectors of attack, including enticing you to malicious web sites, or into interacting with malicious documents or images.
  • 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 in Windows and related components, such as XML Core Services. An attacker could exploit the worst of these flaws to potentially gain complete control of your Windows PC. We recommend you download, test, and deploy these critical updates as quickly as possible.

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

  • MS14-036: Two GDI+ Code Execution Vulnerabilities

The Graphics Device Interface (GDI+) is one of the Windows components that helps applications output graphics, to your display or printer. GDI+ suffers from two security flaws. Though they differ technically, the flaws share the same scope and impact, and have to do with how GDI+ handles specially crafted documents or images. If an attack can entice one of your users into viewing a malicious image or document, perhaps embedded in an email or web site, he can exploit either flaw to execute code on that user’s computer, with that user’s privileges. If your users have local administrative privileges, the attacker gains full control of their computer.

Microsoft rating: Critical

  • MS14-033:  MSXML Information Disclosure Vulnerability

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.

According to today’s bulletin, MSXML suffers from an information disclosure vulnerability. If an attacker can entice one of your users to a specially crafted web site, or into opening a malicious document, she could invoke MSXML and leverage this flaw to obtain sensitive information from your user’s system. Specifically, the attacker can gain access to some local path information, and your user’s username.

Microsoft rating: Important

  • MS14-031:  TCP Protocol Denial of Service Flaw

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 an unspecified Denial of Server (DoS) vulnerability involving its inability to properly parse a specially crafted sequence of TCP packets. By sending a sequence of packets, an attacker could leverage this flaw to cause you computer to stop responding, causing a DoS situation. However, the attacker would have to initiate a large number of connections, and have control over the TCP options field of each packet.

Microsoft rating: Important

  • MS14-030:  RDP traffic tampering vulnerability

The Remote Desktop Protocol (RDP) is a Microsoft communication standard designed to allow you to gain access to your computers over a network to directly control your desktop. Unfortunately, the RDP component that ships with Windows doesn’t use very robust encryption by default. If an attacker can intercept your RDP traffic in a Man-in-the-Middle (MitM) attack, he could tamper with the RDP session in a way that allowed him to read session information or modify the RDP session. You can enable Network Level Authentication (NLA) to mitigate the risk of this flaw

Microsoft rating: Important

Solution Path:

Microsoft has released various 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. As always, you should test your updates before deploying them.

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:

Though WatchGuard’s XTM appliances offer defenses that can mitigate the risk of some of these flaws (such as blocking TCP traffic), attackers can exploit others locally. Since your gateway XTM appliance can’t protect you against local attacks, we 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.

Four Windows Bulletins: Critical TCP/IP Vulnerability Allows Remote Root

Bulletins Affect TCP/IP, Active Directory,  Windows Mail, and More

Severity: High

Summary:

  • These vulnerabilities affect: All current versions of Windows and components that ship with it (though most only affect more recent versions of Windows)
  • How an attacker exploits them: Multiple vectors of attack including sending specially crafted packets, or enticing users into opening booby-trapped files
  • Impact: Various results; in the worst case, an attacker can gain complete control of your Windows computer
  • What to do: Install the appropriate Microsoft patches immediately, or let Windows Automatic Update do it for you.

Exposure:

Today, Microsoft released four security bulletins describing four vulnerabilities that affect Windows and components that ship with it. Each vulnerability affects different versions of Windows to varying degrees, with most of this month’s bulletins affecting Windows Vista, 7, and Server 2008. A remote attacker could exploit the worst of these flaws to gain complete control of your Windows PCs. The summary below lists the vulnerabilities, in order from highest to lowest severity.

  • MS11-083: TCP/IP Remote Code Execution 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 an integer overflow flaw involving its inability to properly parse a continuous flow of specially crafted UDP packets. By sending such packets, an attacker could leverage this flaw to gain complete control of your Windows computer. This flaw only affects Windows Vista, 7, and the Server 2008 versions of Windows. That said, this is a seriously vulnerability, and we recommend you patch it immediately.
Microsoft rating: Critical

  • MS11-085: Windows Mail and Meeting Space Insecure Library Loading Vulnerability

Windows Mail is the default email client that ships with Windows and Meeting Space is a built in document and desktop sharing application.  Unfortunately, both these components suffers from the insecure Dynamic Link Library (DLL) loading class of vulnerability that we’ve described in many previous Microsoft alerts. In a nutshell, this class of flaw involves an attacker enticing one of your users into opening some sort of booby-trapped file from the same location as a specially crafted, malicious DLL file. If you do open the booby-trapped file, it will execute code in the malicious DLL file with your privileges. If you have local administrative privileges, the attacker could exploit this type of issue to gain complete control of your computer. In this particular case, the vulnerability is triggered by files types associated with Mail and Meeting Space–specifically .EML and .WCINV files. 
Microsoft rating: Important.

  • MS11-086: Active Directory Elevation of Privilege Vulnerability

Active Directory (AD) provides central authentication and authorization services for Windows computers and ships with server versions of Windows. Among its many options, AD allows you to authentication using certificates. AD suffers from a certificate handling vulnerability when configured to use LDAP over SSL (LDAPS). In short, AD doesn’t properly recognize revoked SSL certificates, which means an attacker can use a revoked certificate to authenticate and possibly gain access to your systems. However, the attacker would first have to somehow gain access to the revoked certificate for a valid account on your domain to leverage this flaw, which significantly mitigates its severity. If an attacker has access to valid account certificates, revoked or not, you already have a serious problem on your hands.
Microsoft rating: Important.

  • MS11-084: Kernel-mode Driver Denial of  Service Vulnerability

The kernel is the core component of any computer operating system. Windows also ships with a kernel-mode device driver (win32k.sys) which handles many kernel-level devices. The kernel-mode driver suffers from a Denial of Service (DoS) vulnerability involving the way it handles specially crafted TrueType font files. By enticing one of your users to open a specially crafted font file, or to browse to a share hosting such a file, an attacker could exploit this flaw to cause your system to stop responding, until you restart it. This flaw only affects Windows 7 and Server 2008 R2.
Microsoft rating: Moderate.

Solution Path:

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

MS11-083:

MS11-085:

* Server Core installations not affected: If you chose the “Server Core” installation option, Windows does not install unnecessary client applications, such as Mail or Meeting Space.

For All WatchGuard Users:

Attackers can exploit these flaws using diverse exploitation methods. A properly configured firewall can mitigate the risk of some of these issues. That said, the Firebox cannot protect you from local attacks, nor can it prevent attacks that leverage normal HTTP traffic. Therefore, installing Microsoft’s updates is your most secure course of action.

Status:

Microsoft has released patches correcting these issues.

References:

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

Microsoft Black Tuesday: Windows Bulletins Primarily Affect Recent Versions

As expected, today’s Patch Day has a Windows theme, since all of Microsoft’s security bulletins affect Windows or components that ship with it. More importantly, most of the updates primarily affect modern versions of Windows, such as Windows Vista, 7, or Server 2008; only one of the Important bulletins affect older versions of Windows.

A remote code execution flaw in the Windows TCP/IP stack is, by far, the worst flaw this batch of security updates fixes. By sending a stream of specially crafted UDP packets, an attacker could exploit this flaw to gain complete control of a Windows Vista, 7, or Server 2008 computer. UDP packets on any port would work. If you allow any UDP packets through your firewall, attackers could leverage this flaw to pop your computer. I highly recommend you apply Microsoft’s Windows updates as soon as you can, especially if you run a more recent version of Windows.

You can learn more about today’s updates in Microsoft’s November summary bulletin. As is normally the case with Microsoft updates, you should probably test the patches before deploying them in your production network — especially the ones that affect server software.

I’ll post the more detail, consolidated Windows alert here, shortly. Stay tuned. – Corey Nachreiner, CISSP

Six Windows Bulletins Fix Important and Moderate Flaws

Bulletins Affect TCP/IP Stack, Data Access Components, the Kernel, and More

Severity: Medium

Summary:

  • These vulnerabilities affect: All current versions of Windows and components that ship with it
  • How an attacker exploits them: Multiple vectors of attack, including sending specially crafted network packets, enticing your users to open malicious files, or running malicious applications locally
  • Impact: Various results; in the worst case, an attacker can gain complete control of your Windows computer
  • What to do: Install the appropriate Microsoft patches immediately, or let Windows Automatic Update do it for you.

Exposure:

Yesterday, Microsoft released six security bulletins describing seven vulnerabilities that affect Windows and components that ship with it. 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. The summary below lists the vulnerabilities, in order from highest to lowest severity.

  • MS11-059: Data Access Components Code Execution Vulnerability

According to Microsoft, Windows Data Access Components (Windows DAC) help provide access to information across an enterprise. Unfortunately, Windows DAC allows unrestricted access to the loading of external libraries. By enticing one of your users to open a specially crafted Excel file residing in the same location as a malicious DLL file, an attacker could exploit this flaw to execute code on that user’s system, with that users privileges. If your users have local administrative privileges, the attacker gains complete control of their machine. This flaw only affects Windows 7 and later.
Microsoft rating: Important.

  • MS11-061: Remote Desktop Web Access XSS Vulnerability

Windows Remote Desktop (RD) allows you to gain network access to your Windows desktop from anywhere. The Web Access component provides this capability through a web browser. Unfortunately, the RD Web Access component suffers from a Cross-Site Scripting (XSS)  vulnerability. By enticing one of your users into clicking a specially crafted link, an attacker could run script on that users computer under the context of the RD Web Access component, potentially giving the attacker access to your remote desktop. This flaw only affects Windows Server 2008 R2 x64.
Microsoft rating: Important.

  • MS11-062: RAS NDISTAPI Driver Elevation of Privilege Vulnerability

Remote Access Service (RAS) is a component that allows you to access networks over phone lines, and the NDISTAPI driver is one of the RAS components that helps provide this functionality. The NDISTAPI driver doesn’t properly validate users input that it passes to the Windows kernel. By running a specially crafted application, an attacker can leverage this flaw to elevate his privilege, gaining complete control of your Windows machine. However, the attacker would first need to gain local access to your Windows computers using valid credentials, in order to run his special program. This factor significantly reduces the risk of this flaw. Finally, this flaw only affects XP and Server 2003.
Microsoft rating: Important.

  • MS11-063: CSRSS 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 Elevation of Privilege (EoP) vulnerability. Like the NDISTAPI driver flaw above, by running a specially crafted program, an authenticated attacker could leverage these flaws to gain complete, SYSTEM-level  control of your Windows computers. However, like before, the attacker would first need to gain local access to your Windows computers using valid credentials, which somewhat reduces the risk of these flaws.
Microsoft rating: Important.

  • MS11-064: TCP/IP Stack DoS Vulnerabilities

The Windows TCP/IP stack provides IP-based network connectivity to your computer. It suffers from two Denial of Service (DoS) vulnerabilities. On of the flaws is a variant of the very old Ping of Death vulnerability. By sending a specially crafted ICMP message, an attacker can cause your system to stop responding or reboot. Most firewalls, including WatchGuard’s XTM appliances, prevent external exploit of this classic DoS flaw. The second flaw has to do with how the TCP/IP stack handles specially crafted URLs. By sending a specially crafted URL to one of your Windows Web servers, an attacker could exploit this flaw to cause the server to lock up or reboot. These flaws only affect Windows Vista and later.
Microsoft rating: Important.

  • MS11-068: Windows Kernel DoS Vulnerability

The kernel is the core component of any computer operating system. The Windows kernel suffers from a Denial of Service (DoS) vulnerability, involving a flaw in the way it parses metadata in files. By running a specially crafted program, an attacker could leverage this flaw to gain complete control of your Windows computers. However, the attacker would first need to gain local access to your Windows computers using valid credentials. This factor significantly reduces the risk of these flaws. This flaw only affect Windows Vista and later.
Microsoft rating:Moderate.

Solution Path:

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

MS11-059:

MS11-061:

MS11-063:

For All WatchGuard Users:

Attackers can exploit these flaws using diverse exploitation methods. A properly configured firewall can mitigate the risk of some of these issues. That said, the Firebox cannot protect you from local attacks, nor can it prevent attacks that leverage normal HTTP traffic. Therefore, installing Microsoft’s updates is your most secure course of action.

Status:

Microsoft has released patches correcting these issues.

References:

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


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