Multiple unspecified vulnerabilities in mimeTeX, when downloaded before 20090713, have unknown impact and attack vectors related to the (1) \environ, (2) \input, and (3) \counter TeX directives.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2009-2454
http://www.vupen.com/english/advisories/2010/0877
http://www.vupen.com/english/advisories/2009/1875
http://secunia.com/advisories/35752
http://scary.beasts.org/security/CESA-2009-009.html
http://lists.fedoraproject.org/pipermail/package-announce/2010-April/039314.html