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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2011-2939
• https://bugzilla.redhat.com/show_bug.cgi?id=731246
• http://cpansearch.perl.org/src/FLORA/perl-5.14.2/pod/perldelta.pod
• http://perl5.git.perl.org/perl.git/commitdiff/e46d973584785af1f445c4dedbee4243419cb860#patch5
• http://search.cpan.org/~flora/perl-5.14.2/pod/perldelta.pod#Encode_decode_xs_n-byte_heap-overflow_(CVE-2011-2939)
• http://secunia.com/advisories/46172
• http://secunia.com/advisories/46989
• http://secunia.com/advisories/51457
• http://secunia.com/advisories/55314
• http://www.mandriva.com/security/advisories?name=MDVSA-2012:008
• http://www.openwall.com/lists/oss-security/2011/08/18/8
• http://www.openwall.com/lists/oss-security/2011/08/19/17
• http://www.redhat.com/support/errata/RHSA-2011-1424.html
• http://www.securityfocus.com/bid/49858
• http://www.ubuntu.com/usn/USN-1643-1
• https://access.redhat.com/errata/RHSA-2011:1424
• https://access.redhat.com/security/cve/CVE-2011-2939
• http://search.cpan.org/~flora/perl-5.14.2/pod/perldelta.pod#Encode_decode_xs_n-byte_heap-overflow_%28CVE-2011-2939%29