Andrey "SkulleR " Nazarov has identified a security issue in the r1ch.net anticheat module. Insufficient validation of the remote peer combined with other mitigating factors such as DNS poisoning can result in a MITM attack against the anticheat client, which combined with knowledge of the protocol could lead to arbitrary code execution. This issue has been corrected as of this advisory. Affected clients will automatically update the next time they connect to an anticheat-enabled server. To update immediately, download the latest anticheat.dll from http://antiche.at/
or run the R1Q2Updater tool.
Thanks to Andrey Nazarov for discovering and reporting this vulnerability.