-----BEGIN PGP SIGNED MESSAGE----- ============================================================================= FreeBSD-SA-02:25 Security Advisory The FreeBSD Project Topic: bzip2 contains multiple security vulnerabilities Category: core/ports Module: bzip2 Announced: 2002-05-20 Credits: Volker Schmidt, Philippe Troin Affects: FreeBSD 4.4-RELEASE, FreeBSD 4.5-RELEASE, FreeBSD 4.5-STABLE prior to the correction date. bzip2 port prior to bzip2-1.0.2 Corrected: 2002-02-18 09:12:53 UTC (4.5-STABLE, RELENG_4) 2002-02-23 18:28:09 UTC (4.5-RELEASE-p1, RELENG_4_5) 2002-02-23 18:33:18 UTC (4.4-RELEASE-p8, RELENG_4_4) 2002-02-22 13:21:22 UTC (bzip2 port) FreeBSD only: NO I. Background bzip2 is an advanced block-sorting file compression utility. II. Problem Description When creating a file during decompression, the bzip2 utility failed to use the O_EXCL flag, potentially overwriting files without warning. In addition, the bzip2 utility did not securely create new files causing a race condition between creating the file and setting the correct permissions. When compressing a file pointed to by a symbolic link, the bzip2 utility incorrectly stored the permissions of the symbolic link instead of the file. This may result in potentially lax file permissions (rwxr-xr-x), causing the decompressed file to be world-readable. bzip2 was incorporated into FreeBSD prior to FreeBSD 4.4-RELEASE. Previous versions of FreeBSD did not contain bzip2 and are unaffected unless bzip2 was installed from the ports collection or manually by the system administrator. III. Impact 1) Files may be inadvertently overwritten without warning. 2) Due to the race condition between creating files and setting proper permissions, a local user may be able to read the contents of files regardless of their intended permissions. 3) Decompressed files that were originally pointed to by a symbolic link may end up with in incorrect permissions, allowing local users to view their contents. IV. Workaround 1) Deinstall the bzip2 port/package if you have it installed. V. Solution [FreeBSD 4.4 or 4.5 base system] 1) Upgrade your vulnerable system to 4.5-STABLE or the RELENG_4_4 or RELENG_4_5 security branch dated after the respective correction dates. 2) To patch your present system, download the relevant patch from the below location, and execute the following commands as root: # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-02:25/bzip2.patch # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-02:25/bzip2.patch.asc Verify the detached PGP signature using your PGP utility. This patch has been verified to apply to FreeBSD 4.4-RELEASE and 4.5-RELEASE. # cd /usr/src # patch -p < /path/to/patch # cd lib/libbz2 # make depend && make all install # cd ../../usr.bin/bzip2 # make depend && make all install 3) FreeBSD 4.4-RELEASE and 4.5-RELEASE systems: An experimental upgrade package is available for users who wish to provide testing and feedback on the binary upgrade process. This package may be installed on FreeBSD 4.4-RELEASE and 4.5-RELEASE systems only, and is intended for use on systems for which source patching is not practical or convenient. If you use the upgrade package, feedback (positive or negative) to security-officer@FreeBSD.org is requested so we can improve the process for future advisories. During the installation procedure, backup copies are made of the files which are replaced by the package. These backup copies will be reinstalled if the package is removed, reverting the system to a pre-patched state. # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/packages/SA-02.25/security-patch-bzip2-02.25.tgz # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/packages/SA-02.25/security-patch-bzip2-02.25.tgz.asc Verify the detached PGP signature using your PGP utility. # pkg_add security-patch-bzip2-02.25.tgz [ports] 1) Upgrade your entire ports collection and rebuild the bzip2 port. 2) Deinstall the old package and install a new package dated after the correction date, obtained from the following directories: [i386] ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/archivers/ ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/archivers/ [alpha] Packages are not automatically generated for the alpha architecture at this time due to lack of build resources. NOTE: It may be several days before updated packages are available. Be sure to check the file creation date on the package, because the version number of the software has not changed. 3) Download a new port skeleton for the bzip2 port from: http://www.freebsd.org/ports/ and use it to rebuild the port. 4) Use the portcheckout utility to automate option (3) above. The portcheckout port is available in /usr/ports/devel/portcheckout or the package can be obtained from: ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/Latest/portcheckout.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/Latest/portcheckout.tgz VI. Correction details The following list contains the revision numbers of each file that was corrected in FreeBSD. [Ports collection] Path Revision - ------------------------------------------------------------------------- ports/archivers/bzip2/Makefile 1.36 ports/archivers/bzip2/distinfo 1.10 ports/archivers/bzip2/pkg-descr 1.5 ports/archivers/bzip2/pkg-plist 1.14 - ------------------------------------------------------------------------- [Base system] Branch Path Revision - ------------------------------------------------------------------------- RELENG_4 src/contrib/bzip2/CHANGES 1.1.1.1.2.2 src/contrib/bzip2/FREEBSD-upgrade 1.1.2.1 src/contrib/bzip2/LICENSE 1.1.1.1.2.2 src/contrib/bzip2/Makefile 1.1.1.1.2.2 src/contrib/bzip2/Makefile-libbz2_so 1.1.1.1.2.2 src/contrib/bzip2/README 1.1.1.1.2.2 src/contrib/bzip2/README.COMPILATION.PROBLEMS 1.1.1.1.2.2 src/contrib/bzip2/Y2K_INFO 1.1.1.1.2.1 src/contrib/bzip2/blocksort.c 1.1.1.1.2.2 src/contrib/bzip2/bzip2.1 1.1.1.1.2.2 src/contrib/bzip2/bzip2.c 1.1.1.1.2.2 src/contrib/bzip2/bzip2recover.c 1.1.1.1.2.2 src/contrib/bzip2/bzlib.c 1.1.1.1.2.2 src/contrib/bzip2/bzlib.h 1.1.1.1.2.2 src/contrib/bzip2/bzlib_private.h 1.1.1.1.2.2 src/contrib/bzip2/compress.c 1.1.1.1.2.2 src/contrib/bzip2/crctable.c 1.1.1.1.2.2 src/contrib/bzip2/decompress.c 1.1.1.1.2.2 src/contrib/bzip2/dlltest.c 1.1.1.1.2.2 src/contrib/bzip2/huffman.c 1.1.1.1.2.2 src/contrib/bzip2/libbz2.def 1.1.1.1.2.1 src/contrib/bzip2/makefile.msc 1.1.1.1.2.2 src/contrib/bzip2/manual.texi 1.1.1.1.2.2 src/contrib/bzip2/randtable.c 1.1.1.1.2.2 src/contrib/bzip2/sample1.bz2.uu 1.1.1.1.2.2 src/contrib/bzip2/sample1.ref.gz.uu 1.1.1.1.2.2 src/contrib/bzip2/sample2.bz2.uu 1.1.1.1.2.2 src/contrib/bzip2/sample2.ref.gz.uu 1.1.1.1.2.1 src/contrib/bzip2/sample3.bz2.uu 1.1.1.1.2.2 src/contrib/bzip2/sample3.ref.gz.uu 1.1.1.1.2.1 src/contrib/bzip2/spewG.c 1.1.1.1.2.1 src/contrib/bzip2/unzcrash.c 1.1.1.1.2.1 src/contrib/bzip2/words0 1.1.1.1.2.1 src/contrib/bzip2/words1 1.1.1.1.2.1 src/contrib/bzip2/words2 1.1.1.1.2.1 src/contrib/bzip2/words3 1.1.1.1.2.2 RELENG_4_5 src/sys/conf/newvers.sh 1.44.2.20.2.2 src/contrib/bzip2/CHANGES 1.1.1.1.2.1.4.1 src/contrib/bzip2/FREEBSD-upgrade 1.1.4.1 src/contrib/bzip2/LICENSE 1.1.1.1.2.1.4.1 src/contrib/bzip2/Makefile 1.1.1.1.2.1.4.1 src/contrib/bzip2/Makefile-libbz2_so 1.1.1.1.2.1.4.1 src/contrib/bzip2/README 1.1.1.1.2.1.4.1 src/contrib/bzip2/README.COMPILATION.PROBLEMS 1.1.1.1.2.1.4.1 src/contrib/bzip2/Y2K_INFO 1.1.1.1.2.1 src/contrib/bzip2/blocksort.c 1.1.1.1.2.1.4.1 src/contrib/bzip2/bzip2.1 1.1.1.1.2.1.4.1 src/contrib/bzip2/bzip2.c 1.1.1.1.2.1.4.1 src/contrib/bzip2/bzip2recover.c 1.1.1.1.2.1.4.1 src/contrib/bzip2/bzlib.c 1.1.1.1.2.1.4.1 src/contrib/bzip2/bzlib.h 1.1.1.1.2.1.4.1 src/contrib/bzip2/bzlib_private.h 1.1.1.1.2.1.4.1 src/contrib/bzip2/compress.c 1.1.1.1.2.1.4.1 src/contrib/bzip2/crctable.c 1.1.1.1.2.1.4.1 src/contrib/bzip2/decompress.c 1.1.1.1.2.1.4.1 src/contrib/bzip2/dlltest.c 1.1.1.1.2.1.4.1 src/contrib/bzip2/huffman.c 1.1.1.1.2.1.4.1 src/contrib/bzip2/libbz2.def 1.1.1.1.2.1 src/contrib/bzip2/makefile.msc 1.1.1.1.2.1.4.1 src/contrib/bzip2/manual.texi 1.1.1.1.2.1.4.1 src/contrib/bzip2/randtable.c 1.1.1.1.2.1.4.1 src/contrib/bzip2/sample1.bz2.uu 1.1.1.1.2.1.4.1 src/contrib/bzip2/sample1.ref.gz.uu 1.1.1.1.2.1.4.1 src/contrib/bzip2/sample2.bz2.uu 1.1.1.1.2.1.4.1 src/contrib/bzip2/sample2.ref.gz.uu 1.1.1.1.2.1 src/contrib/bzip2/sample3.bz2.uu 1.1.1.1.2.1.4.1 src/contrib/bzip2/sample3.ref.gz.uu 1.1.1.1.2.1 src/contrib/bzip2/spewG.c 1.1.1.1.2.1 src/contrib/bzip2/unzcrash.c 1.1.1.1.2.1 src/contrib/bzip2/words0 1.1.1.1.2.1 src/contrib/bzip2/words1 1.1.1.1.2.1 src/contrib/bzip2/words2 1.1.1.1.2.1 src/contrib/bzip2/words3 1.1.1.1.2.1.4.1 RELENG_4_4 src/sys/conf/newvers.sh 1.44.2.17.2.7 src/contrib/bzip2/CHANGES 1.1.1.1.2.1.2.1 src/contrib/bzip2/FREEBSD-upgrade 1.1.6.1 src/contrib/bzip2/LICENSE 1.1.1.1.2.1.2.1 src/contrib/bzip2/Makefile 1.1.1.1.2.1.2.1 src/contrib/bzip2/Makefile-libbz2_so 1.1.1.1.2.1.2.1 src/contrib/bzip2/README 1.1.1.1.2.1.2.1 src/contrib/bzip2/README.COMPILATION.PROBLEMS 1.1.1.1.2.1.2.1 src/contrib/bzip2/Y2K_INFO 1.1.1.1.2.1 src/contrib/bzip2/blocksort.c 1.1.1.1.2.1.2.1 src/contrib/bzip2/bzip2.1 1.1.1.1.2.1.2.1 src/contrib/bzip2/bzip2.c 1.1.1.1.2.1.2.1 src/contrib/bzip2/bzip2recover.c 1.1.1.1.2.1.2.1 src/contrib/bzip2/bzlib.c 1.1.1.1.2.1.2.1 src/contrib/bzip2/bzlib.h 1.1.1.1.2.1.2.1 src/contrib/bzip2/bzlib_private.h 1.1.1.1.2.1.2.1 src/contrib/bzip2/compress.c 1.1.1.1.2.1.2.1 src/contrib/bzip2/crctable.c 1.1.1.1.2.1.2.1 src/contrib/bzip2/decompress.c 1.1.1.1.2.1.2.1 src/contrib/bzip2/dlltest.c 1.1.1.1.2.1.2.1 src/contrib/bzip2/huffman.c 1.1.1.1.2.1.2.1 src/contrib/bzip2/libbz2.def 1.1.1.1.2.1 src/contrib/bzip2/makefile.msc 1.1.1.1.2.1.2.1 src/contrib/bzip2/manual.texi 1.1.1.1.2.1.2.1 src/contrib/bzip2/randtable.c 1.1.1.1.2.1.2.1 src/contrib/bzip2/sample1.bz2.uu 1.1.1.1.2.1.2.1 src/contrib/bzip2/sample1.ref.gz.uu 1.1.1.1.2.1.2.1 src/contrib/bzip2/sample2.bz2.uu 1.1.1.1.2.1.2.1 src/contrib/bzip2/sample2.ref.gz.uu 1.1.1.1.2.1 src/contrib/bzip2/sample3.bz2.uu 1.1.1.1.2.1.2.1 src/contrib/bzip2/sample3.ref.gz.uu 1.1.1.1.2.1 src/contrib/bzip2/spewG.c 1.1.1.1.2.1 src/contrib/bzip2/unzcrash.c 1.1.1.1.2.1 src/contrib/bzip2/words0 1.1.1.1.2.1 src/contrib/bzip2/words1 1.1.1.1.2.1 src/contrib/bzip2/words2 1.1.1.1.2.1 src/contrib/bzip2/words3 1.1.1.1.2.1.2.1 - ------------------------------------------------------------------------- All files in src/contrib/bzip2 have identical revision numbers on their respective branches but do not contain the revision number in the source code. VII. References -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (FreeBSD) Comment: FreeBSD: The Power To Serve iQCVAwUBPOkduVUuHi5z0oilAQHJtAP/ZoPk981NwyoAzX+BlL9EM0JAl9bYBSmp lgoSORQhK2Cu5DxqOt1J1GIu3748qrAU4+YkZ5JkucA6UgzDFd+mLcQbE57qrDCs rweqLHipm/fjQ8MXFbs5O2ZlrAPTauAiBYk60OtHEoYe5SE70By4zy8o0jzoKo8H 5dXKGYTnve0= =UUGE -----END PGP SIGNATURE-----