Expression Evaluation Bug in Apache HTTP Server by Apache

CVE-2025-54090

What is CVE-2025-54090?

CVE-2025-54090 is a vulnerability affecting the Apache HTTP Server, specifically in version 2.4.64. This issue arises from a bug in the evaluation of expression conditions during the execution of configuration directives. When utilizing the "RewriteCond expr ..." test, this bug causes all such tests to be evaluated as "true," regardless of their actual conditions. The potential consequence of this flaw can be severe, as it may lead to unintended and harmful redirects or to the activation of rewrite rules that the server administrator did not intend to trigger. Organizations relying on Apache HTTP Server for web services may face a range of disruptions, including the possibility of unauthorized access to certain resources, manipulation of web traffic, or unintentional exposure of sensitive information. Upgrading to version 2.4.65 is recommended to remediate this issue and ensure that expression conditions evaluate correctly.

Potential impact of CVE-2025-54090

1. Unauthorized Access: The misconfiguration due to the vulnerability can permit unauthorized users to access restricted areas of a website or application, posing a significant risk of data exposure and security breaches.

2. Manipulated Web Traffic: This flaw enables the possibility of unintentional redirections or rule activations that could be exploited to redirect users to malicious sites or alter the expected behavior of the web service, leading to user mistrust and potential phishing attacks.

3. Increased Attack Surface: By allowing all expression conditions to evaluate as true, CVE-2025-54090 increases the complexity of server configurations and may inadvertently expose hidden vulnerabilities, making the server more susceptible to various forms of cyberattacks.

References