__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Exposure of machine account credentials in winbind log files Samba Security Alert March 30, 2006 18:00 GMT Number Q-159 ______________________________________________________________________________ PROBLEM: winbindd daemon writes text of the machine trust account password to log files. These log files are world readable by default. PLATFORM: Samba Samba 3.0.21 - 3.0.21c DAMAGE: Access allows an attacker to impersonate the server in the domain and gain access to additional information regarding domain users and groups. SOLUTION: Apply current patches ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM - Access allows an attacker to impersonate ASSESSMENT: the server in the domain and gain access to additional information regarding domain users and groups. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/q-159.shtml ORIGINAL BULLETIN: http://us2.samba.org/samba/security/CAN-2006-1059.html CVE: http://www.cve.mitre.org/cgi-bin/cvename.cgi?name= CVE-2006-1059 ______________________________________________________________________________ [****** Start Bulletin Goes Here ******] CAN-2006-1059: Exposure of machine account credentials in winbind log files ========================================================== == == Subject: Exposed clear text of domain machine == account password in debug logs (log == level >= 5) == CVE ID#: CAN_2006-1059 == == Versions: Samba Samba 3.0.21 - 3.0.21c (inclusive) == == Summary: The winbindd daemon writes the clear text == of the machine trust account password to == log files. These log files are world == readable by default. == ========================================================== =========== Description =========== The machine trust account password is the secret shared between a domain controller and a specific member server. Access to the member server machine credentials allows an attacker to impersonate the server in the domain and gain access to additional information regarding domain users and groups. The winbindd daemon included in Samba 3.0.21 and subsequent patch releases (3.0.21a-c) writes the clear text of server's machine credentials to its log file at level 5. The winbindd log files are world readable by default and often log files are requested on open mailing lists as tools used to debug server misconfigurations. This affects servers configured to use domain or ads security and possibly Samba domain controllers as well (if configured to use winbindd). ================== Patch Availability ================== Samba 3.0.22 has been released to address this one security defect. A patch for Samba 3.0.21[a-c] has been posted at http://www.samba.org/samba/security/ An unpatched server may be protected by ensuring that non-administrative users are unable to read any winbindd log files generated at level 5 or greater. ======= Credits ======= This security issue discovered during an internal security audit of the Samba source code by the Samba Team. ========================================================== == Our Code, Our Bugs, Our Responsibility. == The Samba Team ========================================================== [****** End Bulletin Goes Here ******] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Samba 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. 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