centericq 4.20.0-r3 with "Enable peer-to-peer communications" set allows remote attackers to cause a denial of service (segmentation fault and crash) via short zero-length packets, and possibly packets of length 1 or 2, as demonstrated using Nessus.

Multiple integer overflows in libgadu, as used in Kopete in KDE 3.2.3 to 3.4.1, ekg before 1.6rc3, GNU Gadu, CenterICQ, Kadu, and other packages, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via an incoming message.

Stack-based buffer overflow in the LiveJournal support (hooks/ljhook.cc) in CenterICQ 4.9.11 through 4.21.0, when using unofficial LiveJournal servers, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code by adding the victim as a friend and using long (1) username and (2) real name strings.

CenterICQ 4.20.0 and earlier creates temporary files with predictable file names, which allows local users to overwrite arbitrary files via a symlink attack on the gg.token.PID temporary file.