Off-by-one error in the decode_xs function in Unicode/Unicode.xs in the Encode module before 2.44, as used in Perl before 5.15.6, might allow context-dependent attackers to cause a denial of service (memory corruption) via a crafted Unicode string, which triggers a heap-based buffer overflow.
https://bugzilla.redhat.com/show_bug.cgi?id=731246
http://www.ubuntu.com/usn/USN-1643-1
http://www.securityfocus.com/bid/49858
http://www.redhat.com/support/errata/RHSA-2011-1424.html
http://www.openwall.com/lists/oss-security/2011/08/19/17
http://www.openwall.com/lists/oss-security/2011/08/18/8
http://www.mandriva.com/security/advisories?name=MDVSA-2012:008
http://secunia.com/advisories/55314
http://secunia.com/advisories/51457
http://secunia.com/advisories/46989
http://secunia.com/advisories/46172
http://cpansearch.perl.org/src/FLORA/perl-5.14.2/pod/perldelta.pod