ircu 2.10.12.03 and 2.10.12.04 does not associate a timestamp with ops privilege on an unused channel (zannel), which allows remote attackers to (1) set or remove certain channel modes via a “netriding” attack or (2) take over a channel by joining an unlinked server with the A/Upass and then setting a new Apass.

ircu 2.10.12.01 through 2.10.12.04 does not remove ops privilege after a join from a server with an older timestamp (TS), which allows remote attackers to gain control of a channel during a split.

ircu 2.10.12.02 through 2.10.12.04 allows remote attackers to cause a denial of service (memory and bandwidth consumption) by creating a large number of unused channels (zannels).

ircu 2.10.12.01 allows remote attackers to (1) cause a denial of service (flood wallops) by joining two channels with certain long names that differ in the final character, which triggers a protocol violation and (2) cause a denial of service (daemon crash) via a “J 0:#channel” message on a channel without an apass; and (3) allows remote authenticated operators to cause a denial of service (daemon crash) via a remote “names -D” command.