Apache HTTP Server 2.4.39 is running on over 1,800 websites worldwide, but security researchers have identified 2 medium-severity vulnerabilities that could put your site at risk. These CVEs affect critical redirect functionality and URL matching behavior, potentially allowing attackers to manipulate traffic or exploit your web application. Understanding these vulnerabilities and taking immediate action is essential for protecting your website and users from potential attacks.
In this comprehensive guide, we'll walk you through identifying whether your server is vulnerable, explain what these CVEs mean for your security posture, and provide step-by-step instructions to patch and secure your Apache installation. Whether you're a web administrator managing multiple servers or a site owner concerned about your hosting environment, this guide will help you take control of your security.
The good news? These vulnerabilities are fixable, and we'll show you exactly how to do it. Let's dive into the details and get your Apache server secure.
Apache HTTP Server is the most popular open-source web server software globally, powering approximately 30% of all websites on the internet. Version 2.4.39 was released in 2019 and has been widely adopted across hosting providers, enterprise environments, and independent web servers. It's the software responsible for delivering web pages to your visitors' browsers and handling all the requests that come to your website. Think of it as the foundation that makes your website accessible to the world.
The Apache server uses modules—add-on features that extend its functionality—to handle various tasks like rewriting URLs (mod_rewrite) and managing how files are served. Version 2.4.39 contains two security weaknesses in how it processes URL redirects and handles certain URL patterns. These aren't flaws in the basic server operation, but rather specific scenarios where the module behavior can be manipulated, potentially sending users to unintended destinations or bypassing security rules you've set up.
2 CVEs found. The most critical are explained below.
Your website's redirect rules can be tricked by specially formatted requests containing hidden characters. Instead of redirecting users to the correct page within your site, attackers can redirect them to malicious external websites. This happens because your server doesn't properly clean up these hidden characters before processing redirects.
Impact: Visitors could be sent to phishing sites or malware pages without your knowledge, damaging your reputation and potentially compromising user data. Search engines may also penalize your site for redirecting to suspicious locations.
↗ View on NVDA configuration setting called 'MergeSlashes OFF' doesn't work as expected in your Apache server. This means file paths with multiple slashes (like //file.html) may be processed inconsistently, potentially bypassing security rules you've set up. Attackers can exploit this inconsistency to access files or directories they shouldn't reach.
Impact: If you use 'MergeSlashes OFF' for security purposes, those protections may fail silently. Attackers could gain unauthorized access to protected content or bypass access restrictions you've implemented.
↗ View on NVDScan your site in 30 seconds. Used by 500+ web agencies.
Apache 2.4.39 contains two medium-severity vulnerabilities that affect redirect functionality and URL pattern matching—issues that could be exploited to manipulate user traffic or bypass your security configurations. With over 1,800 websites still running this outdated version, the risk is real and measurable. The silver lining is that upgrading to version 2.4.52 or later completely resolves both CVEs, and the process is straightforward when you follow the steps outlined above.
Securing your web server shouldn't be stressful or time-consuming. Use SiteRecipe.com's automated vulnerability scanning tool to continuously monitor your Apache installation for new threats, track your patch status, and receive alerts when updates are available. Our platform helps you stay ahead of security risks so you can focus on growing your business instead of worrying about breaches. Start your free security scan today and join thousands of website owners who trust SiteRecipe.com to keep their servers safe.
Web agencies use SiteRecipe to produce branded PDF security reports in 30 seconds.