Some functions that implement the locale subsystem on Unix do not properly cleanse user-injected format strings, which allows local attackers to execute arbitrary commands via functions such as gettext and catopen.

userhelper in the usermode package on Red Hat Linux executes non-setuid programs as root, which does not activate the security measures in glibc and allows the programs to be exploited via format string vulnerabilities in glibc via the LANG or LC_ALL environment variables (CVE-2000-0844).