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)
108 lines
4.3 KiB
Text
108 lines
4.3 KiB
Text
-----BEGIN PGP SIGNED MESSAGE-----
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=============================================================================
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FreeBSD-SA-01:03 Security Advisory
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FreeBSD, Inc.
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Topic: bash1 creates insecure temporary files
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Category: ports
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Module: bash1
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Announced: 2001-01-15
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Affects: Ports collection prior to the correction date.
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Corrected: 2000-11-29
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Credits: Various
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FreeBSD only: NO
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I. Background
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bash is an enhanced bourne-like shell.
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II. Problem Description
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The bash port, versions prior to the correction date, creates insecure
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temporary files when the '<<' operator is used, by using a predictable
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filename based on the process ID of the shell. An attacker can
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exploit this vulnerability to overwrite an arbitrary file writable by
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the user running the shell. The contents of the file are overwritten
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with the text being entered using the '<<' operator, so it will
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usually not be under the control of the attacker.
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Therefore the likely impact of this vulnerability is a denial of
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service since the attacker can cause critical files writable by the
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user to be overwritten. It is unlikely, although possible depending
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on the circumstances in which the '<<' operator is used, that the
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attacker could exploit the vulnerability to gain privileges (this
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typically requires that they have control over the contents the target
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file is overwritten with).
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This is the same vulnerability as that described in advisory 00:76
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relating to the tcsh/csh shells.
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The bash1 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 nearly 4500 third-party applications in a ready-to-install
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format. The ports collections shipped with FreeBSD 3.5.1 and 4.2 are
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vulnerable to 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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Unprivileged local users can cause an arbitrary file writable by a
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victim to be overwritten when the victim invokes the '<<' operator in
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bash1 (e.g. from within a shell script).
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If you have not chosen to install the bash1 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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Deinstall the bash1 port/package, if you have installed it.
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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 bash1 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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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/shells/bash-1.14.7.tgz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/shells/bash-1.14.7.tgz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/shells/bash-1.14.7.tgz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/shells/bash-1.14.7.tgz
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ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/shells/bash-1.14.7.tgz
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NOTE: Due to an oversight the package version was not updated after
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the security fix was applied, so be sure to install a package created
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after the correction date.
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3) download a new port skeleton for the bash1 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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