Stack-based Buffer Overflow

The glibc packages provide the standard C libraries (libc), POSIX thread libraries (libpthread), standard math libraries (libm), and the Name Server Caching Daemon (nscd) used by multiple programs on the system. Without these libraries, the Linux system cannot function correctly. It was found that getaddrinfo() did not limit the amount of stack memory used during name resolution. An attacker able to make an application resolve an attacker-controlled hostname or IP address could possibly cause the application to exhaust all stack memory and crash. (CVE-2013-1914) A flaw was found in the regular expression matching routines that process multibyte character input. If an application utilized the glibc regular expression matching mechanism, an attacker could provide specially-crafted input that, when processed, would cause the application to crash. (CVE-2013-0242) This update also fixes the following bugs: * The improvements RHSA-2012:1207 made to the accuracy of floating point functions in the math library caused performance regressions for those functions. The performance regressions were analyzed and a fix was applied that retains the current accuracy but reduces the performance penalty to acceptable levels. Refer to Red Hat Knowledge solution 229993, linked to in the References, for further information. (BZ#950535) * It was possible that a memory location freed by the localization code could be accessed immediately after, resulting in a crash. The fix ensures that the application does not crash by avoiding the invalid memory access. (BZ#951493) Users of glibc are advised to upgrade to these updated packages, which contain backported patches to correct these issues.