#VU42618 Input validation error in Fail2ban - CVE-2013-2178

Vulnerability identifier: #VU42618

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2013-2178

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Fail2ban
Server applications / IDS/IPS systems, Firewalls and proxy servers

Vendor: Fail2ban

Description

The vulnerability allows a remote non-authenticated attacker to perform service disruption.

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.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Fail2ban: 0.1.0 - 0.8.8

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External links
https://lists.opensuse.org/opensuse-updates/2014-03/msg00021.html
https://www.debian.org/security/2013/dsa-2708
https://www.openwall.com/lists/oss-security/2013/06/13/7
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A17338
https://raw.github.com/fail2ban/fail2ban/master/ChangeLog
https://vndh.net/note:fail2ban-089-denial-service

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Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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