The remote host is missing an update to irssi announced via advisory MDVSA-2009:133.
To upgrade automatically use MandrakeUpdate or urpmi. The verification of md5 checksums and GPG signatures is performed automatically for you. https://secure1.securityspace.com/smysecure/catid.html?in=MDVSA-2009:133
A vulnerability has been found and corrected in irssi: Off-by-one error in the event_wallops function in fe-common/irc/fe-events.c in irssi 0.8.13 allows remote IRC servers to cause a denial of service (crash) via an empty command, which triggers a one-byte buffer under-read and a one-byte buffer underflow (CVE-2009-1959). This update provides fixes for this vulnerability. Affected: 2008.1, 2009.0, 2009.1, Corporate 3.0