Microsoft Windows users have a huge load of work to do to block attacks using any of the first eight items. So far this year, Microsoft has issued a very large security bulletin every other month with a lighter one issued in between. June is one of the heavy months. Alan
@RISK is the SANS community's consensus bulletin summarizing the most important vulnerabilities and exploits identified during the past week and providing guidance on appropriate actions to protect your systems (PART I). It also includes a comprehensive list of all new vulnerabilities discovered in the past week (PART II).
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Part I is compiled by Rohit Dhamankar (rohitd_at_tippingpoint.com) at TippingPoint, a division of 3Com, as a by-product of that company's continuous effort to ensure that its intrusion prevention products effectively block exploits using known vulnerabilities. TippingPoint's analysis is complemented by input from a council of security managers from twelve large organizations who confidentially share with SANS the specific actions they have taken to protect their systems. A detailed description of the process may be found at http://www.sans.org/newsletters/cva/#process
Description: Microsoft has released a cumulative security update for Internet Explorer - MS05-025, which replaces the previously released update MS05-020. This update fixes the following vulnerabilities: (a) Portable Network Graphics (PNG) is a format for rendering images and used as an alternative to GIF. A PNG image consists of a PNG header followed by a sequence of "chunks" (PNG specification defines 18 such chunk types). Microsoft's PNG library contains a heap-based buffer overflow that can be triggered by a PNG image with a certain large chunk size. This library is used by Internet Explorer for displaying PNG images; hence, a webpage displaying a crafted PNG file can exploit this overflow to execute arbitrary code on a client system. (b) A vulnerability in Internet Explorer can be exploited by a malicious webpage to read local or non-local XML files, potentially providing the attacker with sensitive information. The vulnerability is a variation of the one patched by MS02-047. Proof-of-concept exploit code is publicly available for the older vulnerability. (c) The update also sets the kill bit for the older versions of DigWebX ActiveX control as it reportedly contains a yet undisclosed vulnerability.
Status: Apply the update referenced in Microsoft Security Bulletin MS05-025.
Council Site Actions: All council sites plan to deploy this patch, either during their next regularly scheduled system update process or within the next week.
Description: Microsoft Compiled HTML Help (CHM) files are used to provide the help functionality for any software. The CHM files can be invoked by Internet Explorer via "ms:its", "its" or "mk:@msitstore" protocol handlers. The Windows CHM file parser contains an integer buffer overflow that can be triggered by setting a large length for a size field in the CHM file. A malicious webpage or an HTML email can exploit this flaw to execute arbitrary code on the client system with the privileges of the logged-on user. eEye has posted the technical details that can be used to craft an exploit. NGSSoftware is also credited with the discovery and will release its details in another 3 months.
Status: Apply the update referenced in Microsoft Security Bulletin MS05-026.
Council Site Actions: All council sites plan to deploy this patch during their next regularly scheduled system update process.
Description: Server Message Block (SMB) protocol is used by Windows to share files and printers and to communicate between computers. The server implementation of the protocol contains a heap-based buffer overflow. An anonymous user can exploit this flaw by sending specially crafted SMB messages to execute arbitrary code with kernel privileges. The technical details required to leverage this flaw have not been posted yet. Note that exploiting the flaw to execute arbitrary code is reportedly challenging as it involves kernel shell code.
Status: Apply the update referenced in Microsoft Security Bulletin MS05-026. To prevent exploitation from the Internet, block ports 139/tcp and 445/tcp at the firewall.
Council Site Actions: Most of the council sites plan to deploy this patch, either during their next regularly scheduled system update process or within the next week.
Description: Microsoft Outlook Express can be used as the default newsgroup reader. In this configuration, an attacker can trigger a stack-based buffer overflow in the Outlook Express by sending a specially crafted response to the NTTP LIST command. Specifically, sending an overlong string for the number of "last known article" triggers the overflow that can be exploited to execute arbitrary code with the privileges of the logged-on user. In order to conduct this attack, an attacker can entice a victim to connect to his NNTP server via "news://" URL (in a webpage or an HTML email). However, the victim would need to accept the NNTP server listing prior to successful exploitation.
Status: Apply the update referenced in Microsoft Security Bulletin MS05-030.
Council Site Actions: All council sites plan to deploy this patch, either during their next regularly scheduled system update process or within the next week. One site commented they block NNTP at their network perimeter and they have disabled MSOE in their standards desktop build. Another site commented that their implementation of Cisco Security Agent will detect and stop any attempt to exploit these vulnerabilities.
Description: Microsoft Step-by-Step Interactive Training software is used for interactive training provided by Microsoft Press and other vendors. This software provides a user the ability to bookmark a training topic. The bookmark file is a text file with a ".cbo", ".cbm" or ".cbl" extension. The Interactive Training software contains a stack-based buffer overflow that can be triggered by a bookmark file with an overlong "USER" parameter. A malicious webpage or an HTML e-mail containing a malicious bookmark file can exploit this overflow to execute arbitrary code on a client system with the privileges of the logged-on user. Note that Internet Explorer can automatically open the Interactive bookmark file i.e. no user interaction is required to leverage the flaws on the systems with the Interactive program installed. The iDefense advisory shows how to craft a malicious bookmark file.
Status: Apply the update referenced in Microsoft Security Bulletin MS05-031. Note that this software is not installed by default on most systems, which reduces the risk for this vulnerability.
Council Site Actions: Several reporting council sites plan to deploy this patch during their next regularly scheduled system update process.
Description: Microsoft Agent is a software technology that provides an enhanced user interface for applications and web pages with interactive animated characters. A malicious webpage can use the Microsoft Agent ActiveX control to hide security warnings such as the file download prompts, which may lead to installing malicious code on the client systems. Note that the ActiveX control need not be pre-installed on the systems to exploit this flaw; the attacker's page can lead to its installation.
Status: Apply the update referenced in Microsoft Security Bulletin MS05-032.
Council Site Actions: Several reporting council sites plan to deploy this patch during their next regularly scheduled system update process.
Description: Microsoft's ISA server is vulnerable to the "HTTP Request Smuggling" attacks described in the last issue of the @RISK newsletter. Such attacks can lead to web cache poisoning of the ISA server, or lead to cross-site scripting attacks. The proof-of-concept examples to carry out such attacks have also been posted.
Status: Apply the update referenced in Microsoft Security Bulletin MS05-034. Note that there is no workaround for this vulnerability.
Council Site Actions: Only a few council sites are using the affected software. They plan to deploy the patch during their next regularly scheduled system update process.
Description: The Web Client Service on Windows XP/2003 systems allows users to create and modify files on web servers via WebDAV protocol. This service contains a flaw that can be exploited by authenticated users to execute arbitrary code. Note that this service is enabled by default on Windows XP, and if the "Guest" access is enabled the flaw can be exploited by any user. No technical details regarding how to trigger the vulnerability have been disclosed yet. Note that the service can be also be reached via "DAV RPC SERVICE" named pipe on ports 139/tcp and 445/tcp.
Status: Apply the update referenced in Microsoft Security Bulletin MS05-028. Block ports 139/tcp and 445/tcp to prevent RPC accesses to this service.
Council Site Actions: Only a few council sites are using the affected software. They plan to deploy the patch during their next regularly scheduled system update process.
Description: The Adobe License Management service is installed with certain Adobe products that require product activation. This service contains a buffer overflow that can be exploited to execute arbitrary code with "SYSTEM" privileges. No further technical details about the flaw have been posted yet.
Status: Adobe has released an update for the License Management Service for the affected products.
Council Site Actions: The affected software and/or configuration are not in production or widespread use, or are not officially supported at any of the council sites. They reported that no action was necessary.
Description: Java Web Start Technology is designed for easy deployment of Java-based applications to client desktops. The technology is based on Java Network Launching Protocol and API (JNLP). The JNLP file on a client describes how to download and launch an application. From the workarounds Sun has posted, it appears that a crafted JNLP file may be used to turn-off the "sandbox" restrictions for java applets. This, in turn, may be used to launch malicious applets that download malware to the client system. Sun JRE is also reported to contain a vulnerability that may allow an untrusted applet to elevate privileges. No technical details have been posted about either flaw.
Council Site Actions: The affected software and/or configuration are not in production or widespread use, or are not officially supported at any of the council sites. They reported that no action was necessary. One site said their Sun Java environment is updated on a regular basis to the latest version as part of their standard imaging and maintenance cycle.
This list is compiled by Qualys ( www.qualys.com ) as part of that company's ongoing effort to ensure its vulnerability management web service tests for all known vulnerabilities that can be scanned. As of this week Qualys scans for 4385 unique vulnerabilities. For this special SANS community listing, Qualys also includes vulnerabilities that cannot be scanned remotely.
(c) 2005. All rights reserved. The information contained in this newsletter, including any external links, is provided "AS IS," with no express or implied warranty, for informational purposes only. In some cases, copyright for material in this newsletter may be held by a party other than Qualys (as indicated herein) and permission to use such material must be requested from the copyright owner.
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