The remote host is running a version of the BitchX IRC client that may be vulnerable to a buffer overflow.
A buffer overflow within the DNS resolver code makes it possible to overwrite stack variables by generating a malformed DNS packet. A malicious attacker may use this vulnerability to execute arbitrary code in the context of the BitchX client. Note that it is necessary for an attacker to control a DNS server to exploit this bug.
Upgrade or patch according to vendor recommendations.