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)
110 lines
4.2 KiB
Text
110 lines
4.2 KiB
Text
-----BEGIN PGP SIGNED MESSAGE-----
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=============================================================================
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FreeBSD-SA-00:27 Security Advisory
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FreeBSD, Inc.
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Topic: XFree86-4.0 port contains local root overflow
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Category: ports
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Module: Xfree86-4
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Announced: 2000-07-05
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Credits: Michal Zalewski <lcamtuf@TPI.PL>
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Affects: Ports collection.
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Corrected: 2000-06-09
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Vendor status: Vendor eventually released patch
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FreeBSD only: NO
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I. Background
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XFree86 4.0 is a development version of the popular XFree86 X Windows
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system.
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II. Problem Description
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XFree86 4.0 contains a local root vulnerability in the XFree86 server
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binary, due to incorrect bounds checking of command-line
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arguments.
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The server binary is setuid root, in contrast to previous versions
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which had a small setuid wrapper which performed (among other things)
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argument sanitizing.
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The XFree86-4 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 3400 third-party applications in a ready-to-install
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format. The ports collection shipped with FreeBSD 4.0 contains this
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problem since it was discovered after the release, but it was fixed in
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time for FreeBSD 3.5.
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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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Unprivileged local users can obtain root access.
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If you have not chosen to install the XFree86-4 port/package, then
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your system is not vulnerable to this problem.
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IV. Workaround
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Deinstall the XFree86-4 port/package, if you you have installed it, or
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limit the execution file permissions on the /usr/X11R6/bin/XFree86
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binary so that only members of a trusted group may run the binary.
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V. Solution
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At this time, we do not recommend using XFree86 4.0 on multi-user
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systems with untrusted users, because of the lack of security in the
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server binary. The current "stable" version, XFree86 3.3.6, is also
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available in FreeBSD ports.
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One of the following:
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1) Upgrade your entire ports collection and rebuild the XFree86-4 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:
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/x11/XFree86-4.0.tar.gz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/x11/XFree86-4.0.tar.gz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/x11/XFree86-4.0.tar.gz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/x11/XFree86-4.0.tar.gz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/x11/XFree86-4.0.tar.gz
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An updated version of XFree86, version 4.0.1, has just been released,
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which is believed to also fix the problems detailed in this advisory,
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however the X server is still installed setuid root and so the above
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warning against installation on multi-user machines still applies. The
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packages will be available at the following locations in the next few
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days:
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/x11/XFree86-4.0.1.tar.gz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/x11/XFree86-4.0.1.tar.gz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/x11/XFree86-4.0.1.tar.gz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/x11/XFree86-4.0.1.tar.gz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/x11/XFree86-4.0.1.tar.gz
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3) download a new port skeleton for the XFree86-4 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/packages/devel/portcheckout-1.0.tgz
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