libtasn1-3 - security update

Several vulnerabilities were discovered in libtasn1-3, a library that
manages ASN1 (Abstract Syntax Notation One) structures. An attacker
could use those to cause a denial-of-service via out-of-bounds access
or NULL pointer dereference.

For Debian 6 Squeeze, these issues have been fixed in libtasn1-3 version 2.7-1+squeeze+2