#VU41813 Permissions, Privileges, and Access Controls in ModSecurity - CVE-2013-5705

Vulnerability identifier: #VU41813

Vulnerability risk: Medium

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

CVE-ID: CVE-2013-5705

CWE-ID: CWE-264

Exploitation vector: Network

Exploit availability: No

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

Vendor: Trustwave

Description

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

apache2/modsecurity.c in ModSecurity before 2.7.6 allows remote attackers to bypass rules by using chunked transfer coding with a capitalized Chunked value in the Transfer-Encoding HTTP header.

Mitigation
Install update from vendor's website.

Vulnerable software versions

ModSecurity: 2.0.0 - 2.0.4, 2.1.0 - 2.1.6, 2.5.0 - 2.5.13, 2.6.0 - 2.6.8, 2.7.0 - 2.7.4

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External links
https://martin.swende.se/blog/HTTPChunked.html
https://www.debian.org/security/2014/dsa-2991
https://github.com/SpiderLabs/ModSecurity/commit/f8d441cd25172fdfe5b613442fedfc0da3cc333d

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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.