Description
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 (CVE-2012-3406).
The nss_dns implementation of getnetbyname could run into an infinite loop
if the DNS response contained a PTR record of an unexpected format
(CVE-2014-9402).
Also glibc lock elision (new feature in glibc 2.18) has been disabled
as it can break glibc at runtime on newer Intel hardware (due to hardware
bug)