The Apache HTTP Server is a critical component for hosting web applications around the world. Recently, two major vulnerabilities, CVE-2024-40725 and CVE-2024-40898, have emerged, raising alarm bells across industries.
These vulnerabilities present a serious risk to organizations that rely on the Apache HTTP Server, especially systems using versions 2.4.0 through 2.4.61. According to experts, there are more than 7.6 million cases exposed to possible attacks.
According to a recent report by CYFIRMA, while CVE-2024-40725 affects the mod_proxy module of the Apache HTTP server, CVE-2024-40898 affects the mod_ssl module.
HTTP Request Smuggling and SSL Authentication Bypass
In HTTP request smuggling attacks, an attacker sends multiple crafted HTTP requests, which are misinterpreted by the server due to its faulty handling of HTTP headers. The attacker takes advantage of this misinterpretation to bypass security controls. In the case of CVE-2024-40725, the ProxyPass directive, when misconfigured, can make the server vulnerable to this type of attack.
When the ProxyPass policy is enabled with specific URL rewriting rules, it can lead to HTTP request smuggling attacks. Attackers can exploit this vulnerability to gain unauthorized access to restricted portions of the server, reveal sensitive information, or hijack active user sessions.
The CVE-2024-40898 vulnerability is due to improper verification of SSL client authentication. If SSLVerifyClient is not configured correctly, attackers can bypass the SSL authentication mechanism. This allows them to access sensitive systems without requiring a valid client certificate, thus compromising the security posture of affected organizations.
The existence of PoC exploit codes for both vulnerabilities makes it easier for attackers to target organizations that have not yet applied the necessary patches or updated their configurations. These tools allow attackers to send specially crafted SSL requests to affected servers, which can lead to unauthorized access.
There are already discussions about these vulnerabilities on Dark Web forums, where hackers are actively sharing technical details, targeting information, and exploits, indicating a growing interest in exploiting these vulnerabilities in the wild. These discussions indicate that IP addresses of vulnerable systems are actively circulating, increasing the urgency of taking immediate action.
These vulnerabilities present a high-level threat to organizations, making it imperative that system administrators apply patch updates and review configurations immediately. Without proper mitigation, affected servers could become targets for exploitation, compromising both sensitive information and the integrity of critical systems.
To mitigate the risks, the first and most important step is to apply the latest patch by updating the Apache HTTP server to version 2.4.62 or later. This update addresses both vulnerabilities and provides essential fixes to prevent exploitation.
Additionally, a thorough review of the server configurations is necessary, particularly within the mod_proxy and mod_ssl modules. Ensuring that the ProxyPass policy and URL rewriting settings are securely configured will minimize the risk of HTTP request smuggling, while configuring SSLVerifyClient correctly will prevent authentication bypass attacks.
By implementing a web application firewall (WAF), organizations can filter malicious HTTP and SSL traffic, providing an additional layer of protection against attack attempts. Additionally, performing regular security assessments, including vulnerability scans, helps to proactively identify and address any configuration issues or new vulnerabilities.
Organizations in industries such as finance, healthcare, government, retail, and technology are particularly vulnerable due to the sensitive data they handle. Geographically, regions such as the United States, Germany, India, the Netherlands, and the United Kingdom are considered high-risk areas, given the widespread use of the Apache HTTP server in these locations.
