Stack overflow in libtasn1: libtasn1 is a library to parse ASN.1 data structures. Its most prominent user is GnuTLS.
Fuzzing libtasn1 led to the discovery of a stack write overflow in the function _asn1_ltostr (file parser_aux.c). It overflows a temporary buffer variable on certain inputs. This issue has been reported to the developers on 2015-03-26. A fix was released on 2015-03-29.
The issue can be exposed with Valgrind or Address Sanitizer. The Address Sanitizer output with detailed info is given below.