The PTR_MANGLE implementation in the GNU C Library (aka glibc or libc6) 2.4, 2.17, and earlier, and Embedded GLIBC (EGLIBC) does not initialize the random value for the pointer guard, which makes it easier for context-dependent attackers to control execution flow by leveraging a buffer-overflow vulnerability in an application and using the known zero value pointer guard to calculate a pointer address.

Integer overflow in the vfprintf function in stdio-common/vfprintf.c in glibc 2.14 and other versions allows context-dependent attackers to bypass the FORTIFY_SOURCE protection mechanism, conduct format string attacks, and write to arbitrary memory via a large number of arguments.

Stack-based buffer overflow in the getaddrinfo function in sysdeps/posix/getaddrinfo.c in GNU C Library (aka glibc or libc6) 2.17 and earlier allows remote attackers to cause a denial of service (crash) via a (1) hostname or (2) IP address that triggers a large number of domain conversion results.