Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Wed, 11 Jul 2012 11:18:27 -0600
From: Kurt Seifried <kseifried@...hat.com>
To: oss-security@...ts.openwall.com
CC: Stefan Cornelius <scorneli@...hat.com>
Subject: Re: CVE request: glibc formatted printing vulnerabilities

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 07/11/2012 04:32 AM, Stefan Cornelius wrote:
> Hi,
> 
> there are further vulnerabilities in glibc's formatted printing 
> functionality.
> 
> 1) It was discovered that the formatted printing functionality in
> glibc did not properly honor the size of a structure when
> calculating the amount of memory to allocate. A remote attacker
> could provide a specially crafted sequence of format specifiers,
> leading to an undersized buffer allocation and subsequent stack
> corruption, resulting in a crash or, potentially, FORTIFY_SOURCE
> format string protection mechanism bypass, when processed.
> 
> References: http://sourceware.org/bugzilla/show_bug.cgi?id=12445 
> http://sourceware.org/git/?p=glibc.git;a=commitdiff;h=84a4211850e3d23a9d3a4f3b294752a3b30bc0ff
>
> 
https://bugzilla.redhat.com/show_bug.cgi?id=833703

Please use CVE-2012-3404 for this issue.

> 2) It was discovered that the formatted printing functionality in
> glibc used extend_alloca() incorrectly. "nspecs_max" is incorrectly
> passed to extend_alloca, which modifies the value in "nspecs_max"
> when allocating the memory. A remote attacker could provide a
> specially crafted sequence of format specifiers, leading to a
> desynchronization within the buffer size handling, resulting in the
> use of uninitialized memory or, potentially, FORTIFY_SOURCE format
> string protection mechanism bypass, when processed.
> 
> References: http://sourceware.org/bugzilla/show_bug.cgi?id=13446 
> http://sourceware.org/git/?p=glibc.git;a=commitdiff;h=a4647e727a2a52e1259474c13f4b13288938bed4
>
> 
https://bugzilla.redhat.com/show_bug.cgi?id=833704
> 
> It seems like 1) and 2) were introduced by the following commit: 
> http://sourceware.org/git/?p=glibc.git;a=commitdiff;h=1d498daa95384e5c9ad5bcb35e7a996e5869ac39

Please
> 
use CVE-2012-3405 for this issue.

> 3) It was discovered that the formatted printing functionality in
> glibc did not properly restrict the use of alloca(). A remote
> attacker could provide a specially crafted sequence of format
> specifiers, leading to a crash or, potentially, FORTIFY_SOURCE
> format string protection mechanism bypass, when processed.
> 
> References: https://bugzilla.redhat.com/show_bug.cgi?id=826943
> 
> Red Hat patch backports/testcases for RHEL6 that include a patch
> for this: 
> https://bugzilla.redhat.com/attachment.cgi?id=594722&action=diff
> 
> Red Hat patch backport/testcase for RHEL5 (older glibc versions) 
> https://bugzilla.redhat.com/attachment.cgi?id=594727&action=diff

Please use CVE-2012-3406 for this issue.

> 
> Thanks in advance and kind regards
> 


- -- 
Kurt Seifried Red Hat Security Response Team (SRT)
PGP: 0x5E267993 A90B F995 7350 148F 66BF 7554 160D 4553 5E26 7993



-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
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=g2X7
-----END PGP SIGNATURE-----

Powered by blists - more mailing lists

Your e-mail address:

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.