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.