-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512
=============================================================================
FreeBSD-SA-19:18.bzip2 Security Advisory
The FreeBSD Project
Topic: Multiple vulnerabilities in bzip2
Category: contrib
Module: bzip2
Announced: 2019-08-06
Affects: All supported versions of FreeBSD.
Corrected: 2019-07-04 07:29:18 UTC (stable/12, 12.0-STABLE)
2019-08-06 17:09:47 UTC (releng/12.0, 12.0-RELEASE-p9)
2019-07-04 07:32:25 UTC (stable/11, 11.3-STABLE)
2019-08-06 17:09:47 UTC (releng/11.3, 11.3-RELEASE-p2)
2019-08-06 17:09:47 UTC (releng/11.2, 11.2-RELEASE-p13)
CVE Name: CVE-2016-3189, CVE-2019-12900
For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:https://security.FreeBSD.org/>.
I. Background
The bzip2(1)/bunzip2(1) utilities and the libbz2 library compress and
decompress files using an algorithm based on the Burrows-Wheeler transform.
They are generally slower than Lempel-Ziv compressors such as gzip, but
usually provide a greater compression ratio.
The bzip2recover utility extracts blocks from a damaged bzip2(1) file,
permitting partial recovery of the contents of the file.
II. Problem Description
The decompressor used in bzip2 contains a bug which can lead to an
out-of-bounds write when processing a specially crafted bzip2(1) file.
bzip2recover contains a heap use-after-free bug which can be triggered
when processing a specially crafted bzip2(1) file.
III. Impact
An attacker who can cause maliciously crafted input to be processed
may trigger either of these bugs. The bzip2recover bug may cause a
crash, permitting a denial-of-service. The bzip2 decompressor bug
could potentially be exploited to execute arbitrary code.
Note that some utilities, including the tar(1) archiver and the bspatch(1)
binary patching utility (used in portsnap(8) and freebsd-update(8))
decompress bzip2(1)-compressed data internally; system administrators should
assume that their systems will at some point decompress bzip2(1)-compressed
data even if they never explicitly invoke the bunzip2(1) utility.
IV. Workaround
No workaround is available.
V. Solution
Upgrade your vulnerable system to a supported FreeBSD stable or
release / security branch (releng) dated after the correction date,
and restart daemons if necessary.
1) To update your vulnerable system via a binary patch:
Systems running a RELEASE version of FreeBSD on the i386 or amd64
platforms can be updated via the freebsd-update(8) utility:
# freebsd-update fetch
# freebsd-update install
2) To update your vulnerable system via a source code patch:
The following patches have been verified to apply to the applicable
FreeBSD release branches.
a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.
# fetch https://security.FreeBSD.org/patches/SA-19:18/bzip2.patch
# fetch https://security.FreeBSD.org/patches/SA-19:18/bzip2.patch.asc
# gpg --verify bzip2.patch.asc
b) Apply the patch. Execute the following commands as root:
# cd /usr/src
# patch < /path/to/patch
c) Recompile the operating system using buildworld and installworld as
described in <URL:https://www.FreeBSD.org/handbook/makeworld.html>.
Restart all daemons that use the library, or reboot the system.
VI. Correction details
The following list contains the correction revision numbers for each
affected branch.
Branch/path Revision
- -------------------------------------------------------------------------
stable/12/ r349717
releng/12.0/ r350643
stable/11/ r349718
releng/11.3/ r350643
releng/11.2/ r350643
- -------------------------------------------------------------------------
To see which files were modified by a particular revision, run the
following command, replacing NNNNNN with the revision number, on a
machine with Subversion installed:
# svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base
Or visit the following URL, replacing NNNNNN with the revision number:
<URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN>
VII. References
<URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-3189>
<URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-12900>
The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-19:18.bzip2.asc>
-----BEGIN PGP SIGNATURE-----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=3O6m
-----END PGP SIGNATURE-----
