The parse_datetime function in GNU coreutils allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via a crafted date string, as demonstrated by the "--date=TZ="123"345" @1" string to the touch or date command.
http://advisories.mageia.org/MGASA-2015-0029.html
http://debbugs.gnu.org/cgi/bugreport.cgi?bug=16872
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=766147
http://secunia.com/advisories/62226
https://security.gentoo.org/glsa/201612-22
http://ubuntu.com/usn/usn-2473-1
http://www.openwall.com/lists/oss-security/2014/11/25/1