The remote host is missing an update to ircii announced via advisory DSA 291-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20291-1

Timo Sirainen discovered several problems in ircII, a popular client for Internet Relay Chat (IRC). A malicious server could craft special reply strings, triggering the client to write beyond buffer boundaries. This could lead to a denial of service if the client only crashes, but may also lead to executing of arbitrary code under the user id of the chatting user. For the stable distribution (woody) these problems have been fixed in version 20020322-1.1. For the old stable distribution (potato) these problems have been fixed in version 4.4M-1.1. For the unstable distribution (sid) these problems have been fixed in version 20030315-1. We recommend that you upgrade your ircII package.