Red Hat Security Advisory 2011-1526-03 - The glibc packages contain the standard C libraries used by multiple programs on the system. These packages contain the standard C and the standard math libraries. Without these two libraries, a Linux system cannot function properly. A flaw was found in the way the ldd utility identified dynamically linked libraries. If an attacker could trick a user into running ldd on a malicious binary, it could result in arbitrary code execution with the privileges of the user running ldd. It was found that the glibc addmntent() function, used by various mount helper utilities, did not handle certain errors correctly when updating the mtab file. If such utilities had the setuid bit set, a local attacker could use this flaw to corrupt the mtab file.