Hi guys, since when do we publish security advisories for local DoSes?
On Tue, Oct 25, 2016 at 05:36:41PM +0000, FreeBSD Security Advisories wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA512 > > ============================================================================= > FreeBSD-SA-16:15.sysarch [REVISED] Security Advisory > The FreeBSD Project > > Topic: Incorrect argument validation in sysarch(2) > > Category: core > Module: kernel > Announced: 2016-10-25 > Credits: Core Security, ahaha from Chaitin Tech > Affects: All supported versions of FreeBSD. > Corrected: 2016-10-25 17:14:50 UTC (stable/11, 11.0-STABLE) > 2016-10-25 17:11:20 UTC (releng/11.0, 11.0-RELEASE-p2) > 2016-10-25 17:16:08 UTC (stable/10, 10.3-STABLE) > 2016-10-25 17:11:15 UTC (releng/10.3, 10.3-RELEASE-p11) > 2016-10-25 17:11:11 UTC (releng/10.2, 10.2-RELEASE-p24) > 2016-10-25 17:11:07 UTC (releng/10.1, 10.1-RELEASE-p41) > 2016-10-25 17:16:58 UTC (stable/9, 9.3-STABLE) > 2016-10-25 17:11:02 UTC (releng/9.3, 9.3-RELEASE-p49) > CVE Name: CVE-2016-1885 > > For general information regarding FreeBSD Security Advisories, > including descriptions of the fields above, security branches, and the > following sections, please visit <URL:https://security.FreeBSD.org/>. > > 0. Revision history > > v1.0 2016-03-16 Initial release. > v1.1 2016-10-25 Revised patch to address a problem pointed out by > ahaha from Chaitin Tech. > > I. Background > > The IA-32 architecture allows programs to define segments, which provides > based and size-limited view into the program address space. The > memory-resident processor structure, called Local Descriptor Table, > usually abbreviated LDT, contains definitions of the segments. Since > incorrect or malicious segments would breach system integrity, operating > systems do not provide processes direct access to the LDT, instead > they provide system calls which allow controlled installation and removal > of segments. > > II. Problem Description > > A special combination of sysarch(2) arguments, specify a request to > uninstall a set of descriptors from the LDT. The start descriptor > is cleared and the number of descriptors are provided. Due to lack > of sufficient bounds checking during argument validity verification, > unbound zero'ing of the process LDT and adjacent memory can be initiated > from usermode. > > III. Impact > > This vulnerability could cause the kernel to panic. In addition it is > possible to perform a local Denial of Service against the system by > unprivileged processes. > > IV. Workaround > > No workaround is available, but only the amd64 architecture is affected. > > V. Solution > > Perform one of the following: > > 1) Upgrade your vulnerable system to a supported FreeBSD stable or > release / security branch (releng) dated after the correction date. > > Reboot is required. > > 2) To update your vulnerable system via a binary patch: > > Systems running a RELEASE version of FreeBSD platforms can be updated > via the freebsd-update(8) utility: > > # freebsd-update fetch > # freebsd-update install > > Reboot is required. > > 3) To update your vulnerable system via a source code patch: > > The following patches have been verified to apply to the applicable > FreeBSD release branches. > > [*** v1.1 NOTE ***] If your sources are not yet patched using the initially > published advisory patches, then you need to apply both sysarch.patch and > sysarch-01.patch. If your sources are already updated, or patched with > patches from the initial advisory, then you need to apply sysarch-01.patch > only. > > a) Download the relevant patch from the location below, and verify the > detached PGP signature using your PGP utility. > > [ FreeBSD system not patched with original SA-16:15 patch] > # fetch https://security.FreeBSD.org/patches/SA-16:15/sysarch.patch > # fetch https://security.FreeBSD.org/patches/SA-16:15/sysarch.patch.asc > # gpg --verify sysarch.patch.asc > > [ FreeBSD system that has been patched with original SA-16:15 patch] > # fetch https://security.FreeBSD.org/patches/SA-16:15/sysarch-01.patch > # fetch https://security.FreeBSD.org/patches/SA-16:15/sysarch-01.patch.asc > # gpg --verify sysarch-01.patch.asc > > b) Apply the patch(es). Execute the following commands as root for > every patch file downloaded: > > # cd /usr/src > # patch < /path/to/patch > > c) Recompile your kernel as described in > <URL:https://www.FreeBSD.org/handbook/kernelconfig.html> and reboot the > system. > > VI. Correction details > > The following list contains the correction revision numbers for each > affected branch. > > Branch/path Revision > - ------------------------------------------------------------------------- > stable/9/ r307941 > releng/9.3/ r307931 > stable/10/ r307940 > releng/10.1/ r307932 > releng/10.2/ r307933 > releng/10.3/ r307934 > stable/11/ r307938 > releng/11.0/ r307935 > - ------------------------------------------------------------------------- > > To see which files were modified by a particular revision, run the > following command, replacing NNNNNN with the revision number, on a > machine with Subversion installed: > > # svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base > > Or visit the following URL, replacing NNNNNN with the revision number: > > <URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN> > > VII. References > > <URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-1885> > > The latest revision of this advisory is available at > <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-16:15.sysarch.asc> > -----BEGIN PGP SIGNATURE----- > > iQIcBAEBCgAGBQJYD5VZAAoJEO1n7NZdz2rnYT4QAMmnfUBnxiNHfzaEDMe2oU+H > WIVFzFtU5FTAm3wJ3JORU1euqhusDoB7D8nova30alM2bHHd86epBGgym1Q+hxR2 > qTI+d8QimvQUWelz7DWPh0h3ZNlVfDxY8vKlr5SS0W/HOMjbG/O6U1AIw5p7cPaa > LkDpqo2IN8xBL6tJFUKNEQS/GzuU2HtfKhQK0/ojT4DW61AkOZn4SZzzYBz3iO4p > a8Otv4+aHzyNjTZRm/33SrFzdG0RZWyT/WXsEHlv5NiXVMPML+oY918jppqClkoO > pwjcneWTqgYrE4vvVOADKOlWyNa4jFmPQSW7MmNEaF4RMd8TMcE/cBTKOi41YuOp > la1JzvtWUnou7oQqy/xKr0S/Wa2x6ZhR4vBg28fkfrQhn55N+qqDicQ3F907dOm5 > A0ERHKgImlWSGM+Sf2CJyrUJUNUye0bVQMhrM4e3psZ7Jr20IXjnhppr1mufCjTH > H+aEHv43o/1HuoltnjstiBZ/CZpFdIXkBpsHtzteZR2y+pmZFA9bB4uZeeML0mj3 > /cxj8rgPRmcjk6nSsnLWhq2YEFAZBC/lv43wqSrXE9+BBpSh6zM5NCTPb50/dBqf > V553uuGEvJlHmOAoveXxYyxKcGpgZAcgJjWpAkCpoVxgdrbtLcPY5Z+8cy8fMO3G > YHOkZydbLPaXOXimZfut > =NWuL > -----END PGP SIGNATURE----- > _______________________________________________ > freebsd-security-notificati...@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-security-notifications > To unsubscribe, send any mail to > "freebsd-security-notifications-unsubscr...@freebsd.org" -- Pawel Jakub Dawidek http://www.wheelsystems.com FreeBSD committer http://www.FreeBSD.org Am I Evil? Yes, I Am! http://mobter.com
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