Is CVE-2005-2540 actively exploited?

A proof-of-concept exploit is publicly available for CVE-2005-2540, but active exploitation has not been confirmed.

Can CVE-2005-2540 be exploited remotely?

Yes. CVE-2005-2540 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2005-2540?

CVE-2005-2540 has a CVSS score of 5.0 (MEDIUM).

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MEDIUMPOC

CVE-2005-2540

NVD-CWE-OtherPublished: August 10, 2005· Updated: Jun 16, 2026

5.0

CVSS v3.1

Official Description

CRLF injection vulnerability in FlatNuke 2.5.5 and possibly earlier versions allows remote attackers to execute arbitrary PHP commands via an ASCII char 13 (carriage return) in the signature field, which is injected into a PHP script without a preceding comment character, which can then be executed by a direct request.

NVD Source

Technical Analysis

CVE-2005-2540 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A proof-of-concept (PoC) exploit exists for CVE-2005-2540. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.