The printf wrappers in libsafe 2.0-11 and earlier do not properly handle argument indexing specifiers, which could allow attackers to exploit certain function calls through arguments that are not verified by libsafe.

libsafe 2.0-11 and earlier allows attackers to bypass protection against format string vulnerabilities via format strings that use the "'" and "I" characters, which are implemented in libc but not libsafe.