rennf93 fastapi-guard up to 1.x X-Forwarded-For injection

Summaryinfo

A vulnerability categorized as problematic has been discovered in rennf93 fastapi-guard up to 1.x. This issue affects some unknown processing of the component X-Forwarded-For Handler. Executing a manipulation can lead to injection. This vulnerability is registered as CVE-2025-46814. It is possible to launch the attack remotely. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in rennf93 fastapi-guard up to 1.x. This vulnerability affects an unknown functionality of the component X-Forwarded-For Handler. The manipulation with an unknown input leads to a injection vulnerability. The CWE definition for the vulnerability is CWE-74. The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. As an impact it is known to affect confidentiality. CVE summarizes:

FastAPI Guard is a security library for FastAPI that provides middleware to control IPs, log requests, and detect penetration attempts. An HTTP header injection vulnerability has been identified in versions prior to 2.0.0. By manipulating the X-Forwarded-For header, an attacker can potentially inject arbitrary IP addresses into the request. This vulnerability can allow attackers to bypass IP-based access controls, mislead logging systems, and impersonate trusted clients. It is especially impactful when the application relies on the X-Forwarded-For header for IP-based authorization or authentication. Users should upgrade to FastAPI Guard version 2.0.0 to receive a fix.

The advisory is available at github.com. This vulnerability was named CVE-2025-46814 since 04/30/2025. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1055 by the MITRE ATT&CK project.

Upgrading to version 2.0.0 eliminates this vulnerability. Applying the patch 0b003fda4c678c1b514e95f319aee88113e9bf4b is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Vendor

• rennf93

Name

• fastapi-guard

Version

• 1.x

License

• open-source

Website

• Product: https://github.com/rennf93/fastapi-guard/

CPE 2.3info

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CPE 2.2info

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