Integer signedness error in zip_stream.c in the Zip extension in PHP before 5.3.6 allows context-dependent attackers to cause a denial of service (CPU consumption) via a malformed archive file that triggers errors in zip_fread function calls.
http://bugs.php.net/bug.php?id=49072
http://lists.apple.com/archives/Security-announce/2011//Oct/msg00003.html
http://support.apple.com/kb/HT5002
http://www.debian.org/security/2011/dsa-2266
http://www.php.net/ChangeLog-5.php