The asn1_get_length_der function in decoding.c in GNU Libtasn1 before 2.12, as used in GnuTLS before 3.0.16 and other products, does not properly handle certain large length values, which allows remote attackers to cause a denial of service (heap memory corruption and application crash) or possibly have unspecified other impact via a crafted ASN.1 structure.

Tiny ASN.1 Library (libtasn1) before 0.2.18, as used by (1) GnuTLS 1.2.x before 1.2.10 and 1.3.x before 1.3.4, and (2) GNU Shishi, allows attackers to crash the DER decoder and possibly execute arbitrary code via "out-of-bounds access" caused by invalid input, as demonstrated by the ProtoVer SSL test suite.