The Security Framework in Apple Mac OS X 10.4 through 10.4.8 allows remote attackers to cause a denial of service (resource consumption) via certain public key values in an X.509 certificate that requires extra resources during signature verification. NOTE: this issue may be similar to CVE-2006-2940.
http://www.vupen.com/english/advisories/2006/4750
http://www.us-cert.gov/cas/techalerts/TA06-333A.html
http://www.securityfocus.com/bid/21335
http://securitytracker.com/id?1017298
http://secunia.com/advisories/23155
http://lists.apple.com/archives/security-announce/2006/Nov/msg00001.html