Permissions, Privileges, and Access Controls in GNU C Library (glibc) - CVE-2012-3406

Vulnerability details

The vulnerability allows a remote non-authenticated attacker to read and manipulate data.

The vfprintf function in stdio-common/vfprintf.c in GNU C Library (aka glibc) 2.5, 2.12, and probably other versions does not "properly restrict the use of" the alloca function when allocating the SPECS array, which allows context-dependent attackers to bypass the FORTIFY_SOURCE format-string protection mechanism and cause a denial of service (crash) or possibly execute arbitrary code via a crafted format string using positional parameters and a large number of format specifiers, a different vulnerability than CVE-2012-3404 and CVE-2012-3405.

Affected software

How to mitigate CVE-2012-3406

External References

• http://rhn.redhat.com/errata/RHSA-2012-1097.html
• http://rhn.redhat.com/errata/RHSA-2012-1098.html
• http://rhn.redhat.com/errata/RHSA-2012-1185.html
• http://rhn.redhat.com/errata/RHSA-2012-1200.html
• http://www.openwall.com/lists/oss-security/2012/07/11/17
• http://www.ubuntu.com/usn/USN-1589-1
• https://bugzilla.redhat.com/attachment.cgi?id=594722
• https://bugzilla.redhat.com/show_bug.cgi?id=826943
• https://security.gentoo.org/glsa/201503-04

Related Security Bulletins

• Permissions, Privileges, and Access Controls in Glibc
• Gentoo update for GNU C Library