UnrealIRCd 3.2.8.1, as distributed on certain mirror sites from November 2009 through June 2010, contains an externally introduced modification (Trojan Horse) in the DEBUG3_DOLOG_SYSTEM macro, which allows remote attackers to execute arbitrary commands.

Buffer overflow in UnrealIRCd 3.2beta11 through 3.2.8, when allow::options::noident is enabled, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via unspecified vectors.