Date: Tue, 10 Jul 2001 15:14:30 -0700 From: bow <bow@bow.net> To: freebsd-security@freebsd.org Subject: Where is the patch? (RE: FreeBSD Security Advisory FreeBSD-SA-01:) Message-ID: <20010710151430.A65689@bow.net> In-Reply-To: <200107101402.f6AE2FK63559@freefall.freebsd.org> References: <200107101402.f6AE2FK63559@freefall.freebsd.org>
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At the time of writing this email, I still see no patch on the FreeBSD ftp server. Does anyone know when it is going to be posted or if there is another location where the patch can be obtained? Thanks! -bow On Tue, Jul 10, 2001 at 07:02:15AM -0700, FreeBSD Security Advisories wrote: > -----BEGIN PGP SIGNED MESSAGE----- > > ============================================================================= > FreeBSD-SA-01:42 Security Advisory > FreeBSD, Inc. > > Topic: signal handling during exec may allow local root > compromise > > Category: core > Module: kernel > Announced: 2001-07-10 > Credits: Georgi Guninski <guninski@guninski.com> > Affects: All released versions of FreeBSD 4.x, > FreeBSD 4.3-STABLE prior to the correction date. > Corrected: 2001-07-09 > FreeBSD only: Yes > > I. Background > > When a process forks, it inherits the parent's signals. When the > process execs, the kernel clears the signal handlers because they are > not valid in the new address space. > > II. Problem Description > > A flaw exists in FreeBSD signal handler clearing that would allow for > some signal handlers to remain in effect after the exec. Most of the > signals were cleared, but some signal hanlders were not. This allowed > an attacker to execute arbitrary code in the context of a setuid > binary. > > All versions of 4.x prior to the correction date including and > 4.3-RELEASE are vulnerable to this problem. The problem has been > corrected by copying the inherited signal handlers and resetting the > signals instead of sharing the signal handlers. > > III. Impact > > Local users may be able to gain increased privileges on the local > system. > > IV. Workaround > > Do not allow untrusted users to gain access to the local system. > > V. Solution > > One of the following: > > 1) Upgrade your vulnerable FreeBSD system to 4.3-STABLE after the > correction date. > > 2) To patch your present system: download the relevant patch from the > below location, and execute the following commands as root: > > [FreeBSD 4.1, 4.2, and 4.3 base systems] > > This patch has been verified to apply to FreeBSD 4.1, 4.2, and 4.3 only. > It may or may not apply to older releases. > > # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-01:42/signal-4.3.patch > # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-01:42/signal-4.3.patch.asc > > Verify the detached PGP signature using your PGP utility. > > # cd /usr/src/sys/kern > # patch -p < /path/to/patch > > [ Recompile your kernel as described in > http://www.freebsd.org/handbook/kernelconfig.html and reboot the > system ] > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.0.6 (FreeBSD) > Comment: FreeBSD: The Power To Serve > > iQCVAwUBO0sBrlUuHi5z0oilAQF4nAP/Wi8RsYGjJQ7NgP/+FwMs8/lekAJ9iEan > 3Ph7xpsFEhJFWhCfrhmM71fMnOwpZ5kijztSOEko7TMRzTtG+dZLKcCKmVg+a1dT > SJmm2SJp3NE1nlYVqSH1vfVeVcJI5rtAQ33gTPhiL5U26AMr4wep/Elv1p/Shb/D > CUpueXr6tEE= > =n74Z > -----END PGP SIGNATURE----- > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-security" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message
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