3571e53040
patches for easier mirroring, to eliminate a special copy, to make www.freebsd.org/security a full copy of security.freebsd.org and be eventually be the same. For now files are just sitting there. The symlinks are missing. Discussed on: www (repository location) Discussed with: simon (so)
124 lines
4.6 KiB
Text
124 lines
4.6 KiB
Text
-----BEGIN PGP SIGNED MESSAGE-----
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=============================================================================
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FreeBSD-SA-01:65 Security Advisory
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FreeBSD, Inc.
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Topic: Buffer overflow in libgtop_server
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Category: ports
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Module: libgtop
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Announced: 2001-12-11
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Credits: Flavio Veloso <flaviovs@magnux.com>
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Affects: Ports collection prior to the correction date
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Corrected: 2001-11-29 15:06:19 UTC
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FreeBSD only: NO
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I. Background
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libgtop is a library for gtop, the GNOME version of the top command.
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The top command is a tool to display and update information about the
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top cpu processes.
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II. Problem Description
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The libgtop port versions prior to libgtop-1.0.12_1 contain a stack
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buffer overflow in libgtop_server, allowing an arbitrary amount of
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data from the client application (assumed to be gtop) to be read
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into a fixed-sized buffer. A local attacker can exploit this bug to
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cause libgtop_server to execute arbitrary code. libgtop_server runs
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with increased privileges as a member of group kmem, which allows
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it to read kernel memory (but not write it). A process with the
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ability to read from kernel memory can monitor privileged data such as
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network traffic, disk buffers and terminal activity, and may be able
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to leverage this to obtain further privileges on the local system or
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on other systems, including root privileges.
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The libgtop port is not installed by default, nor is it "part of
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FreeBSD" as such: it is part of the FreeBSD ports collection, which
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contains over 6000 third-party applications in a ready-to-install
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format. The ports collection shipped with FreeBSD 4.4 contains this
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problem since it was discovered after the release.
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FreeBSD makes no claim about the security of these third-party
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applications, although an effort is underway to provide a security
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audit of the most security-critical ports.
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III. Impact
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A successful exploit of this stack buffer overflow would allow an
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attacker arbitrary access to kernel memory, possibly acquiring
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information allowing further increases in privileges.
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No exploit is known to exist at this time, and it is not known
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whether this buffer overflow is exploitable even in theory. In any
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case, local access to the machine on which libgtop_server is running
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is required to attempt an attack.
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IV. Workaround
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1) Deinstall the libgtop port/package if you have it installed.
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OR
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2) Remove the setgid bit from the libgtop_server executable by
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executing the following command as root:
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# chmod g-s `which libgtop_server`
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V. Solution
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1) Upgrade your entire ports collection and rebuild the port.
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2) Deinstall the old package and install a new package dated after the
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correction date, obtained from the following directories:
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[i386]
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/devel/libgtop-1.0.12_1.tar.gz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/devel/libgtop-1.0.12_1.tar.gz
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[alpha]
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Packages are not automatically generated for the alpha architecture at
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this time due to lack of build resources.
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NOTE: It may be several days before updated packages are available. Be
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sure to check the file creation date on the package, because the
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version number of the software has not changed.
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3) Download a new port skeleton for the libgtop port from:
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http://www.freebsd.org/ports/
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and use it to rebuild the port.
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4) Use the portcheckout utility to automate option (3) above. The
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portcheckout port is available in /usr/ports/devel/portcheckout or the
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package can be obtained from:
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/devel/portcheckout-2.0.tgz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/devel/portcheckout-2.0.tgz
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VI. Correction details
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The following list contains the revision numbers of each file that was
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corrected in the FreeBSD ports collection.
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Path Revision
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- -------------------------------------------------------------------------
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ports/devel/libgtop/Makefile 1.45
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ports/devel/libgtop/files/patch-src::daemon::gnuserv.c 1.1
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- -------------------------------------------------------------------------
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VII. References
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<URL:http://www.securityfocus.com/archive/1/242922>
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