Julien Cristau discovered that hybserv, a daemon running IRC services for IRCD-Hybrid, is prone to a denial of service attack via the commands option. For the stable distribution , this problem has been fixed in version 1.9.2-4+lenny2. Due to a bug in the archive system, it is not possible to release the fix for the oldstable distribution simultaneously. Therefore, etch will be fixed in version 1.9.2-4+etch1 as soon as it becomes available. For the testing distribution , this problem will be fixed soon. For the unstable distribution , this problem has been fixed in version 1.9.2-4.1. We recommend that you upgrade your hybserv packages.