=============================================================================
FreeBSD-SA-04:14.cvs.asc                                  Security Advisory
                                                          The FreeBSD Project

Topic:          CVS

Category:       contrib
Module:         cvs
Announced:      2004-09-19
Credits:        Stefan Esser, Sebastian Krahmer, Derek Price
                iDEFENSE
Affects:        All FreeBSD versions
Corrected:      2004-06-29 16:10:50 UTC (RELENG_4)
                2004-09-19 22:26:22 UTC (RELENG_4_10, 4.10-RELEASE-p3)
                2004-09-19 22:27:36 UTC (RELENG_4_9, 4.9-RELEASE-p12)
                2004-09-19 22:28:14 UTC (RELENG_4_8, 4.8-RELEASE-p25)
                2004-09-19 22:37:10 UTC (RELENG_5_2, 5.2.1-RELEASE-p10)
CVE Name:       CAN-2004-0414, CAN-2004-0416, CAN-2004-0417, CAN-2004-0418,
                CAN-2004-0778
FreeBSD only:   NO

For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit
http://www.freebsd.org/security/>.

I.   Background

The Concurrent Versions System (CVS) is a version control system.  It
may be used to access a repository locally, or to access a `remote
repository' using a number of different methods.  When accessing a
remote repository, the target machine runs the CVS server to fulfill
client requests.

II.  Problem Description

A number of vulnerabilities were discovered in CVS by Stefan Esser,
Sebastian Krahmer, and Derek Price.

 . Insufficient input validation while processing "Entry" lines.
   (CAN-2004-0414)

 . A double-free resulting from erroneous state handling while
   processing "Argumentx" commands. (CAN-2004-0416)

 . Integer overflow while processing "Max-dotdot" commands.
   (CAN-2004-0417)

 . Erroneous handling of empty entries handled while processing
   "Notify" commands. (CAN-2004-0418)

 . A format string bug while processing CVS wrappers.

 . Single-byte buffer underflows while processing configuration files
   from CVSROOT.

 . Various other integer overflows.

Additionally, iDEFENSE reports an undocumented command-line flag used
in debugging does not perform input validation on the given path
names.

III. Impact

CVS servers ("cvs server" or :pserver: modes) are affected by these
vulnerabilities.  They vary in impact but include information disclosure
(the iDEFENSE-reported bug), denial-of-service (CAN-2004-0414,
CAN-2004-0416, CAN-2004-0417 and other bugs), or possibly arbitrary code
execution (CAN-2004-0418).  In very special situations where the
attacker may somehow influence the contents of CVS configuration files
in CVSROOT, additional attacks may be possible.

IV.  Workaround

Disable the use of remote CVS repositories.

V.   Solution

Do one of the following:

1) Upgrade your vulnerable system to the RELENG_4 stable branch, or to
the RELENG_5_2, RELENG_4_10, RELENG_4_9, or RELENG_4_8 security branch
dated after the correction date.

OR

2) Patch your present system:

The following patches have been verified to apply to FreeBSD 4.8, 4.9,
4.10 and 5.2.1 systems.  Note that one *must* have previously applied
the patches pertaining to FreeBSD-SA-04:10.cvs in order to use these
patches.

Note that FreeBSD 4.10-STABLE systems built from sources dated
2004-06-29 16:20:00 UTC or later include cvs 1.11.17, which has all
of these issues fixed.  These patches should not be applied to those
systems.

a) Download the relevant patches from the location below, and verify the
detached PGP signature using your PGP utility.

# fetch  ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:14/cvs.patch
# fetch  ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:14/cvs.patch.asc

b) Execute the following commands as root:

# cd /usr/src
# patch < /path/to/patch
# cd /usr/src/gnu/usr.bin/cvs
# 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_10
  src/UPDATING                                              1.73.2.90.2.4
  src/sys/conf/newvers.sh                                   1.44.2.34.2.5
  src/contrib/cvs/lib/xsize.h                                 1.1.1.1.6.1
  src/contrib/cvs/src/commit.c                                1.8.2.5.6.1
  src/contrib/cvs/src/cvs.h                                  1.11.2.6.6.1
  src/contrib/cvs/src/filesubr.c                              1.6.2.4.6.1
  src/contrib/cvs/src/history.c                           1.1.1.6.2.4.6.1
  src/contrib/cvs/src/modules.c                           1.1.1.5.2.4.2.1
  src/contrib/cvs/src/server.c                               1.13.2.5.6.3
  src/contrib/cvs/src/wrapper.c                           1.1.1.7.2.3.6.1
  src/gnu/usr.bin/cvs/lib/config.h.proto                     1.16.2.1.6.1
RELENG_4_9
  src/UPDATING                                             1.73.2.89.2.13
  src/sys/conf/newvers.sh                                  1.44.2.32.2.13
  src/contrib/cvs/lib/xsize.h                                 1.1.1.1.8.1
  src/contrib/cvs/src/commit.c                                1.8.2.5.4.1
  src/contrib/cvs/src/cvs.h                                  1.11.2.6.4.1
  src/contrib/cvs/src/filesubr.c                              1.6.2.4.4.1
  src/contrib/cvs/src/history.c                           1.1.1.6.2.4.4.1
  src/contrib/cvs/src/modules.c                           1.1.1.5.2.3.4.2
  src/contrib/cvs/src/server.c                               1.13.2.5.4.3
  src/contrib/cvs/src/wrapper.c                           1.1.1.7.2.3.4.1
  src/gnu/usr.bin/cvs/lib/config.h.proto                     1.16.2.1.4.1
RELENG_4_8
  src/UPDATING                                             1.73.2.80.2.28
  src/sys/conf/newvers.sh                                  1.44.2.29.2.26
  src/contrib/cvs/lib/xsize.h                                1.1.1.1.10.1
  src/contrib/cvs/src/commit.c                                1.8.2.5.2.1
  src/contrib/cvs/src/cvs.h                                  1.11.2.6.2.1
  src/contrib/cvs/src/filesubr.c                              1.6.2.4.2.1
  src/contrib/cvs/src/history.c                           1.1.1.6.2.4.2.1
  src/contrib/cvs/src/modules.c                           1.1.1.5.2.3.2.2
  src/contrib/cvs/src/server.c                               1.13.2.5.2.3
  src/contrib/cvs/src/wrapper.c                           1.1.1.7.2.3.2.1
  src/gnu/usr.bin/cvs/lib/config.h.proto                     1.16.2.1.2.1
RELENG_5_2
  src/UPDATING                                                 1.282.2.18
  src/sys/conf/newvers.sh                                       1.56.2.17
  src/contrib/cvs/lib/xsize.h                                1.1.1.1.12.1
  src/contrib/cvs/src/commit.c                                   1.13.4.1
  src/contrib/cvs/src/cvs.h                                      1.17.4.1
  src/contrib/cvs/src/filesubr.c                                 1.10.6.1
  src/contrib/cvs/src/history.c                              1.1.1.10.6.1
  src/contrib/cvs/src/modules.c                               1.1.1.8.6.3
  src/contrib/cvs/src/server.c                                   1.19.4.4
  src/contrib/cvs/src/wrapper.c                              1.1.1.10.6.1
  src/gnu/usr.bin/cvs/lib/config.h.proto                         1.17.2.1
-------------------------------------------------------------------------

VII. References

http://security.e-matters.de/advisories/092004.html >