Bug 741107 - kernel timestamps prevent fail2ban detecting sshd brute force attacks
Summary: kernel timestamps prevent fail2ban detecting sshd brute force attacks
Alias: None
Product: Fedora
Classification: Fedora
Component: fail2ban
Version: 15
Hardware: Unspecified
OS: Unspecified
Target Milestone: ---
Assignee: Axel Thimm
QA Contact: Fedora Extras Quality Assurance
Depends On:
TreeView+ depends on / blocked
Reported: 2011-09-25 12:20 UTC by Adam Spiers
Modified: 2012-08-07 14:55 UTC (History)
2 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2012-08-07 14:55:34 UTC

Attachments (Terms of Use)

Description Adam Spiers 2011-09-25 12:20:25 UTC
Something changed at some point since Fedora 11, and now some messages from userspace daemons include kernel timestamps in their syslog text, e.g.

Sep 25 12:51:04 myhost kernel: [773580.832329] sshd[25557]: Invalid user pgsql from

Unfortunately fail2ban does not recognise this extra 'kernel: \[\d+\.\d+\]' text, which means that it fails to detect sshd brute force attacks, and probably many other kinds of attacks.

Seen on Fedora 15 with fail2ban-0.8.4-27.fc15.noarch

Steps to Reproduce:
1. Install fail2ban on F15
2. Configure sshd jail and start fail2ban service
3. Simulate sshd attack by ssh'ing to machine with non-existent user names multiple times
Actual results:
fail2ban takes no action

Expected results:
fail2ban should ban IP from which ssh attempts originate.

I have submitted a bug and patch upstream (sourceforge) to fix this:


but it doesn't look like fail2ban's sourceforge project is being maintained very actively.  On github I found a more active git-svn clone of the sourceforge svn repo, forked that, and patched it:


Comment 1 Fedora End Of Life 2012-08-07 14:55:38 UTC
This message is a notice that Fedora 15 is now at end of life. Fedora
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