Net::DNS is "a DNS resolver implemented in Perl. It allows the programmer to perform nearly any type of DNS query from a Perl script". beSTORM's DNS Server module has been able to detect a vulnerability in Net::DNS allows a malicious server to cause the Net::DNS package to crash by sending it a malformed DNS response, this in turn would cause any product using the package to crash with it.
http://www.securiteam.com/unixfocus/6I00E0UKKQ.html
