Quake II server before R1Q2, as used in multiple products, allows remote attackers to corrupt the server's client state data structure by exiting a session…

Quake II server before R1Q2, as used in multiple products, allows remote attackers to corrupt the server's client state data structure by exiting a session without a valid disconnect command, then reconnecting, which prevents a mod from being notified of changes in the client state. NOTE: the impact of this issue will vary depending on which mod is being used.