__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Vulnerability in Snort DCE/RPC Preprocessor [2007-02-19 Sourcefire Advisory] February 20, 2007 21:00 GMT Number R-146 ______________________________________________________________________________ PROBLEM: This preprocessor is vulnerable to a stack-based buffer that could potentially allow attackers to execute code with the same privilieges as the Snort binary. PLATFORM: Snort Versions Affected: Snort 2.6.1, 2.6.1.1, and 2.6.1.2 Snort 2.7.0 beta 1 DAMAGE: Could potentially allow attackers to execute code with the same privileges as the Snort binary. SOLUTION: Upgrade to the appropriate version. ______________________________________________________________________________ VULNERABILITY The risk is HIGH. Could potentially allow attackers to execute ASSESSMENT: code with the same privileges as the Snort binary. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/r-145.shtml ORIGINAL BULLETIN: http://www.snort.org/docs/advisory-2007-02-19.html CVE: http://www.cve.mitre.org/cgi-bin/cvename.cgi?name= CVE-2006-5276 ______________________________________________________________________________ [***** Start 2007-02-19 Sourcefire Advisory *****] 2007-02-19 Sourcefire Advisory: Vulnerability in Snort DCE/RPC Preprocessor Summary: Sourcefire has learned of a remotely exploitable vulnerability in the Snort DCE/RPC preprocessor. This preprocessor is vulnerable to a stack-based buffer overflow that could potentially allow attackers to execute code with the same privileges as the Snort binary. Sourcefire has prepared updates for Snort open-source software to address this issue. This vulnerability has been identified as CVE-2006-5276. Snort Versions Affected: Snort 2.6.1, 2.6.1.1, and 2.6.1.2 Snort 2.7.0 beta 1 This vulnerability also affects Sourcefire commercial products. For information and updates for Sourcefire products, please go to the Sourcefire support site. Mitigating Factors: Users who have disabled the DCE/RPC preprocessor are not vulnerable. However, the DCE/RPC preprocessor is enabled by default. Recommended Actions: Open-source Snort 2.6.1.x users are advised to upgrade to Snort 2.6.1.3 (or later) immediately. Open-source Snort 2.7 beta users are advised to mitigate this issue by disabling the DCE/RPC preprocessor. This issue will be resolved in Snort 2.7 beta 2. Workarounds: Snort users who cannot upgrade immediately are advised to disable the DCE/RPC preprocessor by removing the DCE/RPC preprocessor directives from snort.conf and restarting Snort. However, be advised that disabling the DCE/RPC preprocessor reduces detection capabilities for attacks in DCE/RPC traffic. After upgrading, customers should reenable the DCE/RPC preprocessor. Detecting Attacks Against This Vulnerability: Sourcefire will be releasing a rule pack that provides detection for attacks against this vulnerability. FAQs: What does the update do? Snort 2.6.1.3 (or later) removes the vulnerability by correcting the buffer overflow condition in the DCE/RPC preprocessor. Has Sourcefire received any reports that this vulnerability has been exploited? No. Sourcefire has not received any reports that this vulnerability has been exploited. Acknowledgments: Sourcefire would like to thank Neel Mehta from IBM X-Force for reporting this issue and working with us to resolve it. [***** End 2007-02-19 Sourcefire Advisory *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Snort 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. CIAC can be contacted at: Voice: +1 925-422-8193 (7x24) FAX: +1 925-423-8002 STU-III: +1 925-423-2604 E-mail: ciac@ciac.org Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://www.ciac.org/ Anonymous FTP: ftp.ciac.org PLEASE NOTE: Many users outside of the DOE, ESnet, and NIH computing communities receive CIAC bulletins. If you are not part of these communities, please contact your agency's response team to report incidents. Your agency's team will coordinate with CIAC. The Forum of Incident Response and Security Teams (FIRST) is a world-wide organization. A list of FIRST member organizations and their constituencies can be obtained via WWW at http://www.first.org/. This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes. 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