The _cupsGetlang function, as used by lppasswd.c in lppasswd in CUPS 1.2.2, 1.3.7, 1.3.9, and 1.4.1, relies on an environment variable to determine the file that provides localized message strings, which allows local users to gain privileges via a file that contains crafted localization data with format string specifiers.
https://bugzilla.redhat.com/show_bug.cgi?id=558460
http://www.ubuntu.com/usn/USN-906-1
http://www.securityfocus.com/bid/38524
http://www.mandriva.com/security/advisories?name=MDVSA-2010:073
http://www.mandriva.com/security/advisories?name=MDVSA-2010:072
http://www.cups.org/str.php?L3482
http://support.apple.com/kb/HT4077
http://security.gentoo.org/glsa/glsa-201207-10.xml
http://lists.apple.com/archives/security-announce/2010//Mar/msg00001.html