Description
The apache-auth.conf, apache-nohome.conf, apache-noscript.conf, and apache-overflows.conf files in Fail2ban before 0.8.10 do not properly validate log messages, which allows remote attackers to block arbitrary IP addresses via certain messages in a request.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | fail2ban | 0.8.10-1 | — |
| Debian 13 | fail2ban | 0.8.10-1 | — |
| Debian 12 | fail2ban | 0.8.10-1 | — |
| Debian 7 | fail2ban | 0.8.6-3wheezy2 | DSA-2708-1 |
| Debian 6.0 | fail2ban | 0.8.4-3+squeeze2 | DSA-2708-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | fail2ban | 0.9.5-1.1 | openSUSE-SU-2024:10347-1 |
Advisories 2
- DSA-2708-1 fail2ban - denial of service Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10347-1 SuSEfirewall2-fail2ban-0.9.5-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- oval:org.mitre.oval:def:17338 vdb-entry signature
- [oss-security] 20130613 Re: Re: Fail2ban 0.8.9, Denial of Service (Apache rules only) mailing-list
- DSA-2708 vendor-advisory
- openSUSE-SU-2014:0348 vendor-advisory
- https://raw.github.com/fail2ban/fail2ban/master/ChangeLog
- https://vndh.net/note:fail2ban-089-denial-service