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)
99 lines
3.6 KiB
Text
99 lines
3.6 KiB
Text
-----BEGIN PGP SIGNED MESSAGE-----
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=============================================================================
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FreeBSD-SA-00:46 Security Advisory
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FreeBSD, Inc.
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Topic: screen port contains local root compromise
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Category: ports
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Module: screen
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Announced: 2000-09-13
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Affects: Ports collection prior to the correction date.
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Corrected: 2000-09-01
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Credits: Jouko Pynnönen <jouko@SOLUTIONS.FI>
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Vendor status: Updated version released
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FreeBSD only: NO
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I. Background
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screen is a popular application that multiplexes a physical terminal
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between several processes.
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II. Problem Description
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The screen port, versions 3.9.5 and before, contains a vulnerability
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which allows local users to gain root privileges. This is
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accomplished by inserting string-formatting operators into
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configuration parameters, which may allow arbitrary code to be
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executed.
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The screen 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 3800 third-party applications in a ready-to-install
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format. The ports collections shipped with FreeBSD 3.5.1 and 4.1
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contain this problem since it was discovered after the releases.
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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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Local users can obtain root privileges.
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If you have not chosen to install the screen port/package, then your
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system is not vulnerable to this problem.
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IV. Workaround
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Remove the setuid bit on the program: execute the following command as
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root:
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chmod 555 /usr/local/bin/screen-3.9.5
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Note that this should be considered a temporary measure and may affect
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the behaviour of the screen program.
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V. Solution
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One of the following:
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1) Upgrade your entire ports collection and rebuild the screen 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/misc/screen-3.9.8.tgz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/misc/screen-3.9.8.tgz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/misc/screen-3.9.8.tgz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/misc/screen-3.9.8.tgz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/misc/screen-3.9.8.tgz
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NOTE: It may be several days before updated packages are available.
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3) download a new port skeleton for the screen 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-3-stable/devel/portcheckout-2.0.tgz
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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/alpha/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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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/devel/portcheckout-2.0.tgz
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