Input validation error in Fail2ban

1) Input validation error

EUVDB-ID: #VU43223

Risk: Medium

CVSSv3.1: 6.4 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2012-5642

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to read and manipulate data.

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.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Fail2ban: 0.1.0 - 0.8.7

External links

http://lists.opensuse.org/opensuse-updates/2013-04/msg00001.html
http://lists.opensuse.org/opensuse-updates/2013-04/msg00002.html
http://sourceforge.net/mailarchive/message.php?msg_id=30193056
http://www.mandriva.com/security/advisories?name=MDVSA-2013:078
http://www.openwall.com/lists/oss-security/2012/12/17/2
http://bugs.gentoo.org/show_bug.cgi?id=447572
http://bugzilla.redhat.com/show_bug.cgi?id=887914
http://github.com/fail2ban/fail2ban/commit/83109bc
http://raw.github.com/fail2ban/fail2ban/master/ChangeLog

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.