Mega-Fence up to 25.1.914 Header webgate-lib.* X-Forwarded-For access control

Summaryinfo

A vulnerability classified as problematic has been found in Mega-Fence up to 25.1.914. The impacted element is an unknown function in the library webgate-lib.* of the component Header Handler. Performing a manipulation of the argument X-Forwarded-For results in access control. This vulnerability is known as CVE-2025-65328. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Mega-Fence up to 25.1.914. This affects some unknown processing in the library webgate-lib.* of the component Header Handler. The manipulation of the argument X-Forwarded-For with an unknown input leads to a access control vulnerability. CWE is classifying the issue as CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. This is going to have an impact on integrity. The summary by CVE is:

Mega-Fence (webgate-lib.*) 25.1.914 and prior trusts the first value of the X-Forwarded-For (XFF) header as the client IP without validating a trusted proxy chain. An attacker can supply an arbitrary XFF value in a remote request to spoof the client IP, which is then propagated to security-relevant state (e.g., WG_CLIENT_IP cookie). Deployments that rely on this value for IP allowlists may be bypassed.

It is possible to read the advisory at drive.proton.me. This vulnerability is uniquely identified as CVE-2025-65328 since 11/18/2025. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 01/06/2026). The attack technique deployed by this issue is T1068 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-0812). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

• Mega-Fence

Version

• 25.1.914

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CPE 2.2info

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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