CVE-2007-1659
Perl-Compatible Regular Expression (PCRE) library before 7.3 allows context-dependent attackers to cause a denial of service (crash) and possibly execute arbitrary code via regex patterns containing unmatched "QE" sequences with orphan "E" codes.
Date published : 2007-11-07
http://lists.apple.com/archives/security-announce/2007/Dec/msg00002.html
http://lists.apple.com/archives/security-announce/2008/Mar/msg00001.html