Multiple shell programs on various Unix systems, including (1) tcsh, (2) csh, (3) sh, and (4) bash, follow symlinks when processing << redirects (aka here-documents or in-here documents), which allows local users to overwrite files of other users via a symlink attack.
Format string vulnerability in talkd in OpenBSD and possibly other BSD-based OSes allows remote attackers to execute arbitrary commands via a user name that contains format characters.
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.
Kernel logging daemon (klogd) in Linux does not properly cleanse user-injected format strings, which allows local users to gain root privileges by triggering malformed kernel messages.
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).
Buffer overflow in kon program in Kanji on Console (KON) package on Linux may allow local users to gain root privileges via a long -StartupMessage parameter.