server/action.py in Fail2ban before 0.8.8 does not properly handle the content of the matches tag, which might allow remote attackers to trigger unsafe behavior in a custom action file via unspecified symbols in this content.

This update of fail2ban fixes a startup related startup-problem and a security problem fixed upstream (CVE-2012-5642).

Updated fail2ban package fixes security vulnerability :

fail2ban before 0.8.8 didn't escape the content of \<matches\> (if used in custom action files), which could cause issues on the system running fail2ban as it scans log files, depending on what content is matched, since that content could contain arbitrary symbols (CVE-2012-5642).

Update to 0.8.8 (CVE-2012-5642 Bug #887914)

  - Fixes :

    - Alan Jenkins

    - [8c38907] Removed 'POSSIBLE BREAK-IN ATTEMPT' from       sshd filter to avoid banning due to misconfigured DNS.
      Close gh-64

  - Yaroslav Halchenko

    - [83109bc] IMPORTANT: escape the content of <matches>       (if used in custom action files) since its value could       contain arbitrary symbols. Thanks for discovery go to       the NBS System security team

  - [b159eab] do not enable pyinotify backend if pyinotify <     0.8.3

    - [37a2e59] store IP as a base, non-unicode str to avoid       spurious messages in the console. Close gh-91

  - New features :

    - David Engeset

    - [2d672d1,6288ec2] 'unbanip' command for the client +       avoidance of touching the log file to take 'banip' or       'unbanip' in effect. Close gh-81, gh-86

  - Yaroslav Halchenko

    - Enhancements :

    - [2d66f31] replaced uninformative 'Invalid command'       message with warning log exception why command       actually failed

  - [958a1b0] improved failregex to 'support' auth.backend =     'htdigest'

    - [9e7a3b7] until we make it proper module -- adjusted       sys.path only if system-wide run

  - [f52ba99] downgraded 'already banned' from WARN to INFO     level. Closes gh-79

    - [f105379] added hints into the log on some failure       return codes (e.g. 0x7f00 for this gh-87)

  - Various others: travis-ci integration, script to run     tests against all available Python versions, etc

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
74950	openSUSE Security Update : fail2ban (openSUSE-SU-2013:0566-1)	Nessus	SuSE Local Security Checks	high
66092	Mandriva Linux Security Advisory : fail2ban (MDVSA-2013:078)	Nessus	Mandriva Local Security Checks	high
63496	Fedora 18 : fail2ban-0.8.8-1.fc18 (2012-20589)	Nessus	Fedora Local Security Checks	high
63343	Fedora 17 : fail2ban-0.8.8-1.fc17 (2012-20619)	Nessus	Fedora Local Security Checks	high

Detections

Analytics

CVE-2012-5642

high

Tenable Plugins

high

high

high

high