__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Apache mod_tcl Module Contains a Format String Error [US-CERT Vulnerability Note VU#366020] November 8, 2006 18:00 GMT Number R-031 ______________________________________________________________________________ PROBLEM: A format string vulnerability exists in the mod_tcl Apache module. PLATFORM: Apache 2.x mod_tcl module 1.0 DAMAGE: May allow a remote attacker to execute arbitrary code. SOLUTION: Upgrade to the appropriate version. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. May allow a remote attacker to execute ASSESSMENT: arbitrary code. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/r-031.shtml ORIGINAL BULLETIN: US-CERT Vulnerability Note VU#366020 http://www.kb.cert.org/vuls/id/366020 CVE: http://www.cve.mitre.org/cgi-bin/cvename.cgi?name= CVE-2006-4154 ______________________________________________________________________________ [***** Start US-CERT Vulnerability Note VU#366020 *****] Vulnerability Note VU#366020 Apache mod_tcl module contains a format string error Overview A format string vulnerability exists in the mod_tcl Apache module. This vulnerability may allow a remote attacker to execute arbitrary code. I. Description The Apache HTTP Server, also known as httpd, is an open-source HTTP server that runs on Microsoft Windows, Linux, Unix, and Apple OS X Operating Systems. Apache modules can be used to extend the functionality of the Apache web server. The mod_tcl module is a scripting module that allows Apache to run TCL scripts natively. There is a format string vulnerability in the mod_tcl module that may allow an attacker to execute arbitrary code. II. Impact A remote, unauthenticated attacker may be able to execute arbitrary code with the privileges of the httpd process. III. Solution Upgrade The mod_tcl team has released an upgrade that addresses this issue. Install only required modules Only install the modules that are necessary for the operation of the web server. Restrict access Restricting access to a vulnerable system to trusted hosts until an upgrade can be applied may mitigate the affects of this vulnerability. Systems Affected Vendor Status Date Updated Apache HTTP Server Project Vulnerable 7-Nov-2006 References http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=421 http://secunia.com/advisories/22458/ http://xforce.iss.net/xforce/xfdb/29550 http://security.gentoo.org/glsa/glsa-200610-12.xml http://secunia.com/advisories/22549/ Credit Thanks to the mod_tcl and Gentoo teams for providing information about this vulnerability. This document was written by Ryan Giobbi. Other Information Date Public 10/14/2006 Date First Published 11/07/2006 01:54:13 PM Date Last Updated 11/07/2006 CERT Advisory CVE Name CVE-2006-4154 Metric 3.99 Document Revision 27 If you have feedback, comments, or additional information about this vulnerability, please send us email. [***** End US-CERT Vulnerability Note VU#366020 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of US-CERT for the information contained in this bulletin. _______________________________________________________________________________ CIAC, the Computer Incident Advisory Capability, is the computer security incident response team for the U.S. Department of Energy (DOE) and the emergency backup response team for the National Institutes of Health (NIH). CIAC is located at the Lawrence Livermore National Laboratory in Livermore, California. CIAC is also a founding member of FIRST, the Forum of Incident Response and Security Teams, a global organization established to foster cooperation and coordination among computer security teams worldwide. CIAC services are available to DOE, DOE contractors, and the NIH. 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