__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Samba 'call_trans2open' Remote Buffer Overflow Vulnerability [Samba (7 Apr, 2003) Security Advisory] April 7, 2003 18:00 GMT Number N-073 ______________________________________________________________________________ PROBLEM: A buffer overflow vulnerability in Samba occurs in the 'call_trans2open()' function when copying data into a 1024 byte static buffer. Sufficent bounds checking is not carried out to prevent this vulnerability. AFFECTED SOFTWARE: All versions of Samba up to and including Samba 2.2.8. DAMAGE: This vulnerability could allow an anonymous remote attacker to execute arbitrary code with super user privileges by sending data in excess of 1024 bytes. SOLUTION: Upgrade to Samba 2.2.8a. ______________________________________________________________________________ VULNERABILITY The risk is HIGH. An active exploit of this vulnerability has ASSESSMENT: been reported in the wild. A successful remote attacker could potentially overwrite sensitive stack variables. Subsequently, an ability to influence sensitive memory could be used to execute arbitrary code with the Samba server process privileges, typically root. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/n-073.shtml ORIGINAL BULLETIN: http://us2.samba.org/samba/samba.html UPGRADE: SEE SECTION TITLED: Samba News dated 7 Apr, 2003 Security Advisory, Samba 2.2.8a security available for download. ______________________________________________________________________________ [***** Start Samba (7 Apr, 2003) Security Advisory *****] (7 Apr, 2003) Security Advisory - Samba 2.2.8a security available for download Digital Defense, Inc. has alerted the Samba Team to a serious vulnerability in all stable versions of Samba currently shipping. The Common Vulnerabilities and Exposures (CVE) project has assigned the ID CAN-2003-0201 to this defect. This vulnerability, if exploited correctly, leads to an anonymous user gaining root access on a Samba serving system. All versions of Samba up to and including Samba 2.2.8 are vulnerable. An active exploit of the bug has been reported in the wild. Alpha versions of Samba 3.0 and above are *NOT* vulnerable. The 2.2.8a release contains only updates to address this security issue. A rollup patch for release 2.2.7a and 2.0.10 addressing both CAN-2003-0201 and CAN-2003-0085 can be obtained from this directory. The source tarball is available in both gzip format and bzip2 format. The uncompressed tarball signature should also be downloaded to verify the archive's integrity. Here is the Samba Distribution Key for verifying the tarball. Finally, here is the patchfile against 2.2.8 (signature). [***** End Samba (7 Apr, 2003) Security Advisory *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Samba and Symantec Corp. 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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