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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2005.0694 -- FreeBSD-SA-05:20.cvsbug Race condition in cvsbug 12 September 2005 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: cvsbug Publisher: FreeBSD Operating System: FreeBSD Impact: Execute Arbitrary Code/Commands Inappropriate Access Access: Existing Account CVE Names: CAN-2005-2693 Ref: ESB-2005.0691 Revision History: September 12 2005: Additional related issues fixed in FreeBSD 4.10 and 5.3 September 8 2005: Initial Release - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ============================================================================= FreeBSD-SA-05:20.cvsbug Security Advisory The FreeBSD Project Topic: Race condition in cvsbug Category: contrib Module: contrib_cvs Announced: 2005-09-07 Credits: Marcus Meissner Affects: All FreeBSD releases Corrected: 2005-09-07 13:43:05 UTC (RELENG_6, 6.0-BETA5) 2005-09-07 13:43:23 UTC (RELENG_5, 5.4-STABLE) 2005-09-07 13:43:36 UTC (RELENG_5_4, 5.4-RELEASE-p7) 2005-09-09 19:26:19 UTC (RELENG_5_3, 5.3-RELEASE-p22) 2005-09-07 13:44:06 UTC (RELENG_4, 4.11-STABLE) 2005-09-07 13:44:20 UTC (RELENG_4_11, 4.11-RELEASE-p12) 2005-09-09 19:24:22 UTC (RELENG_4_10, 4.10-RELEASE-p18) CVE Name: CAN-2005-2693 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit <URL:http://www.freebsd.org/security/>. 0. Revision History v1.0 2005-07-07 Initial release. v1.1 2005-07-09 Additional related issues fixed in FreeBSD 4.10 and 5.3. I. Background cvsbug(1) is a utility for reporting problems in the CVS revision control system. It is based on the GNATS send-pr(1) utility. II. Problem Description A temporary file is created, used, deleted, and then re-created with the same name. This creates a window during which an attacker could replace the file with a link to another file. While cvsbug(1) is based on the send-pr(1) utility, this problem does not exist in the version of send-pr(1) distributed with FreeBSD. In FreeBSD 4.10 and 5.3, some additional problems exist concerning temporary file usage in both cvsbug(1) and send-pr(1). III. Impact A local attacker could cause data to be written to any file to which the user running cvsbug(1) (or send-pr(1) in FreeBSD 4.10 and 5.3) has write access. This may cause damage in itself (e.g., by destroying important system files or documents) or may be used to obtain elevated privileges. IV. Workaround Do not use the cvsbug(1) utility on any system with untrusted users. Do not use the send-pr(1) utility on a FreeBSD 4.10 or 5.3 system with untrusted users. V. Solution Perform one of the following: 1) Upgrade your vulnerable system to 4-STABLE or 5-STABLE, or to the RELENG_5_4, RELENG_5_3, RELENG_4_11, or RELENG_4_10 security branch dated after the correction date. 2) To patch your present system: The following patches have been verified to apply to FreeBSD 4.10, 4.11, 5.3, and 5.4 systems. a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility. [FreeBSD 4.10] # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:20/cvsbug410.patch # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:20/cvsbug410.patch.asc [FreeBSD 5.3] # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:20/cvsbug53.patch # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:20/cvsbug53.patch.asc [FreeBSD 4.11 and 5.4] # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:20/cvsbug.patch # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:20/cvsbug.patch.asc b) Execute the following commands as root: # cd /usr/src # patch < /path/to/patch # cd /usr/src/gnu/usr.bin/cvs/cvsbug # make obj && make depend && make && make install # cd /usr/src/gnu/usr.bin/send-pr # make obj && make depend && make && make install VI. Correction details The following list contains the revision numbers of each file that was corrected in FreeBSD. Branch Revision Path - - ------------------------------------------------------------------------- RELENG_4 src/contrib/cvs/src/cvsbug.in 1.1.1.1.2.4 RELENG_4_11 src/UPDATING 1.73.2.91.2.13 src/sys/conf/newvers.sh 1.44.2.39.2.16 src/contrib/cvs/src/cvsbug.in 1.1.1.1.2.3.2.1 RELENG_4_10 src/UPDATING 1.73.2.90.2.19 src/sys/conf/newvers.sh 1.44.2.34.2.20 src/contrib/cvs/src/cvsbug.in 1.1.1.1.2.2.6.2 src/gnu/usr.bin/send-pr/send-pr.sh 1.13.2.13.2.1 RELENG_5 src/contrib/cvs/src/cvsbug.in 1.1.1.3.2.1 RELENG_5_4 src/UPDATING 1.342.2.24.2.16 src/sys/conf/newvers.sh 1.62.2.18.2.12 src/contrib/cvs/src/cvsbug.in 1.1.1.3.6.1 RELENG_5_3 src/UPDATING 1.342.2.13.2.25 src/sys/conf/newvers.sh 1.62.2.15.2.27 src/contrib/cvs/src/cvsbug.in 1.1.1.3.4.1 src/gnu/usr.bin/send-pr/send-pr.sh 1.35.6.1 RELENG_6 src/contrib/cvs/src/cvsbug.in 1.1.1.3.8.1 - - ------------------------------------------------------------------------- VII. References http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-2693 The latest revision of this advisory is available at ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-05:20.cvsbug.asc - -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (FreeBSD) iD8DBQFDIeKFFdaIBMps37IRApOpAJ9RRKHLnuyFOuaM1pN09Sn3Rysv4gCgiF+/ QJ1c9krguLbujP/YL4LaDP0= =5W0R - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. 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Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 If you believe that your computer system has been compromised or attacked in any way, we encourage you to let us know by completing the secure National IT Incident Reporting Form at: http://www.auscert.org.au/render.html?it=3192 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQCVAwUBQyTCCCh9+71yA2DNAQL5UgP/THGiOWoSkGoB8fwUpTNt+ZCpeNVxTuTF KwF8mGmavD5R17cjWy9hEDlLRK7FutnNORyGF3v0tw2XiffCrQ2EwO3xHWeQHnpz YKZZL8zSRT6Kgh8qq9IWBx2TG12bmBhzJXAusyohYUXS8RuuO5wX7O8g5CExc2Bs aLduZMV4C8I= =Pead -----END PGP SIGNATURE-----