Mozilla (Suite) before 1.7.1, Firefox before 0.9.2, and Thunderbird before 0.7.2 allow remote attackers to launch arbitrary programs via a URI referencing the shell: protocol.
https://exchange.xforce.ibmcloud.com/vulnerabilities/16655
http://www.mozilla.org/security/shell.html
http://www.mozilla.org/projects/security/known-vulnerabilities.html
http://www.kb.cert.org/vuls/id/927014
http://www.ciac.org/ciac/bulletins/o-175.shtml
http://secunia.com/advisories/12027
http://marc.info/?l=bugtraq&m=108938712815719&w=2
http://lists.grok.org.uk/pipermail/full-disclosure/2004-July/023573.html