Integer underflow in the ksba_oid_to_str function in Libksba before 1.3.2, as used in GnuPG, allows remote attackers to cause a denial of service (crash) via a crafted OID in a (1) S/MIME message or (2) ECC based OpenPGP data, which triggers a buffer overflow.
http://www.ubuntu.com/usn/USN-2427-1
http://www.securityfocus.com/bid/71285
http://www.mandriva.com/security/advisories?name=MDVSA-2015:151
http://www.mandriva.com/security/advisories?name=MDVSA-2014:234
http://www.debian.org/security/2014/dsa-3078
http://secunia.com/advisories/60233
http://secunia.com/advisories/60189
http://secunia.com/advisories/60073
http://lists.gnupg.org/pipermail/gnupg-announce/2014q4/000359.html