The first critical vulnerability this week, in ClamAV, is in open source software used in many email, web and FTP antivirus (AV) scanning gateways running on UNIX/Linux. Apple Mac, Linux, IBM, Sun, and others are referenced in the supporting pages as possible users. If you employ gateway AV on systems with those operating systems, check with your vendor for applicability.
And once more Firefox web browser and Symantec's Veritas storage products have critical new vulnerabilities that allow attackers to take over and control systems running those software packages.
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 for this issue has been compiled by Dinesh Sequeira and Rohit Dhamankar at TippingPoint, a division of 3Com, (www.tippingpoint.com) 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: ClamAV is an open-source antivirus program designed mainly for scanning emails on UNIX mail gateways. The software includes a virus scanning library - libClamAV. This library is used by many third party email, web, FTP scanners as well as mail clients. The library contains a buffer overflow in the file "upx.c" that can be triggered by specially crafted UPX (Packed Executable Format) packed executable files. A denial of service flaw also exists in the file "fsg.c" that can cause the ClamAV engine to enter an infinite loop while processing crafted FSG files. The attacker can send the malicious files via email, web, FTP or a file share, and exploit the flaws to either execute arbitrary code on the system running the ClamAV library, or cause a denial of service. The technical details can be obtained by comparing the fixed and the affected versions of the software. Note that for compromising the mail/web/FTP gateways no user interaction is required.
Status: The vendor has released ClamAV 0.87 to address these issues. Please look for third party updates for the software.
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: This vulnerability in Mozilla/FireFox browsers and Thunderbird email client can be exploited to execute arbitrary commands on UNIX systems. The problem occurs when a URL containing "backtick" is passed as an argument to Mozilla, Firefox or Thunderbird. For instance, issuing a command "firefox http://local\`ls`\" will result in the execution of the 'ls' command. Systems using Mozilla/Firefox as default browsers and Thunderbird as default email client are at a higher risk as visiting a malicious webpage may result in the execution of attacker specified commands.
Status: Updates have been released to address this issue for Mozilla and Firefox.
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. Most reported that no action was necessary. A few sites have advised the users to upgrade to the latest version. One site plans to distribute patches during their next regularly scheduled system update process.
Description: TWiki, Perl-based CGI software, allows multiple users to manage a web site's content through a web browser. TWiki is popularly used for intranet content management by many companies. The revision control function included in the software contains a command execution vulnerability. The problem occurs because the user input to the revision control function's "rev" parameter is not properly sanitized for shell metacharacters such as "|"(pipe). This can be exploited by an unauthenticated attacker to execute arbitrary commands on the web server. The posted advisory shows how to construct a malicious HTTP request.
Status: TWiki has confirmed and patches are available. Note that TWikiRelease 01September2004 patched with Florian Weimer's patch ( http://www.enyo.de/fw/security/notes/twiki-robustness.html) is not vulnerable.
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: AhnLab and AVIRA family of products are designed to protect desktops and servers from various viruses. These products contain a buffer overflow in processing ACE archives. In case of AVIRA products, the overflow is triggered by an ACE archive containing a compressed file with a long filename. (Possibly a similar issue for the AhnLab products.) If the compressed file scanning is enabled, this overflow can be exploited to execute arbitrary code on the systems running Ahnlab or AVIRA anti-virus products. In addition, AhnLab anti-virus also contains a directory traversal vulnerability that can be exploited to write arbitrary files (for example in the "Startup" folder on Windows).
Status: AhnLab and AVIRA have published updates to address these issues.
Council Site Actions: Only one of the reporting council sites responded to this item. They are currently testing the hotfix and commented that affected clients do not browse the Internet. The remaining council sites do not use the affected software.
Description: VERITAS Storage Exec and StorageCentral are file storage solutions from VERITAS. Multiple remote heap and stack buffer overflows exist, due to improper bounds checking of input data on StorageCentral and Storage Exec's DCOM Servers. The buffer overflows in the DCOM servers can be successfully initiated by calls to associated ActiveX controls. An attacker can entice a user to visit a hostile website or send a malicious link in an email, and thus compromise the system. NGSSoftware, credited for the discovery of these issues, has not posted any technical details yet.
Status: Hotfix available from vendor.
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: Exploit code has been publicly posted for the IDN URI buffer overflow in Mozilla, Firefox and Netscape browsers discussed in the previous issue of the @RISK newsletter.
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