USN-5232-1: Fail2ban vulnerability
12 September 2022
Fail2ban could be made to run programs as an administrator.
Releases
Packages
- fail2ban - ban hosts that cause multiple authentication errors
Details
Jakub Żoczek discovered that certain Fail2ban actions handled whois responses in
an insecure way. If Fail2ban was configured to use certain mail actions
like 'mail-whois' on a target system, a remote attacker who was able to control whois
responses to this target system could possibly execute arbitrary code.
Update instructions
The problem can be corrected by updating your system to the following package versions:
Ubuntu 20.04
-
fail2ban
-
0.11.1-1ubuntu0.1~esm1
Available with Ubuntu Pro
Ubuntu 18.04
-
fail2ban
-
0.10.2-2ubuntu0.1~esm1
Available with Ubuntu Pro
Ubuntu 16.04
-
fail2ban
-
0.9.3-1ubuntu0.1~esm1
Available with Ubuntu Pro
Ubuntu 14.04
-
fail2ban
-
0.8.11-1ubuntu0.1~esm1
Available with Ubuntu Pro
In general, a standard system update will make all the necessary changes.