CVE-2024-40725 and CVE-2024-40898 Vulnerabilities in Apache’s HTTP Server : Vulnerability Analysis and Exploitation

EXECUTIVE SUMMARY

CVE-2024-40725 and CVE-2024-40898 are vulnerabilities in Apache’s HTTP Server. CVE-2024-40725 affects the mod_proxy module, where enabling the ProxyPass directive with specific URL rewrite rules can lead to HTTP Request Smuggling, potentially causing unauthorized access, data exposure, and security breaches. CVE-2024-40898 impacts the mod_ssl module, where the improper configuration of the SSLVerifyClient directive can allow authentication bypass, granting unauthorized access to sensitive systems. Discussions on underground forums indicate that affected device IP addresses are circulating on the deep/dark web. Immediate patching is essential to mitigate these risks.

INTRODUCTION

CVE-2024-40725 and CVE-2024-40898 are critical vulnerabilities in the Apache HTTP Server, raising significant security concerns across various industries and regions. With over 7.4 million internet-exposed instances at risk, these flaws reintroduce previously patched issues, making them particularly alarming. CVE-2024-40725 can be exploited through HTTP Request Smuggling attacks, allowing attackers to execute malicious code without authentication. These vulnerabilities pose a severe threat to sensitive systems and data, requiring urgent action.

KEY TAKEAWAYS AND ACKNOWLEDGEMENTS

Key Takeaways:

• Attack Vector: HTTP Request Smuggling through mod_proxy.
• Potential Impact: Information disclosure, unauthorized data access, and further exploitation of backend systems.
• Underground Activity: Active exploitation discussions and circulation of vulnerable IP addresses on dark web forums increase the urgency of addressing this vulnerability.
• Organizations must promptly apply security patches, review and update configurations, and enhance monitoring to defend against potential exploitation of this vulnerability.

Acknowledgements:
The CYFIRMA research team acknowledges security researchers who responsibly disclosed this vulnerability.

VULNERABILITY AT A GLANCE

Vulnerability Type: HTTP Request Smuggling and SSL Client Authentication Bypass
CVE ID: CVE-2024-40725 and CVE-2024-40898
CVSS Severity Score: 7.5 (High)
Application: Apache
Impact: Allowing authentication bypass, allowing unauthorized access to the system or sensitive information
Severity: High
Affected Versions: Apache HTTP Server versions 2.4.0 through 2.4.61
Patch Available: Yes

DESCRIPTION

CVE-2024-40725 and CVE-2024-40898 are serious vulnerabilities affecting the Apache HTTP Server. CVE-2024-40725 targets the mod_proxy module, where enabling the ProxyPass directive with specific URL rewrite rules can enable HTTP Request Smuggling attacks, leading to unauthorized access and potential data breaches. CVE-2024-40898 impacts the mod_ssl module, where misconfiguring the SSLVerifyClient directive could enable authentication bypass, granting attackers unauthorized access to systems and sensitive information. These vulnerabilities require immediate attention.

IMPACT

CVE-2024-40725 can result in HTTP Request Smuggling attacks, leading to unauthorized access, information disclosure, session hijacking, and potential data theft or manipulation. CVE-2024-40898 enables authentication bypass, which can lead to unauthorized system access, exposure of sensitive information, and potential further exploitation, such as privilege escalation or additional attacks.

AFFECTED VERSIONS

CVE-2024-40725 and CVE-2024-40898 impact Apache’s HTTP Server versions 2.4.0 through 2.4.61. All instances running these versions are vulnerable and should be patched immediately to mitigate the associated risks.

SECURITY INDICATORS

Is there already an exploit tool to attack this vulnerability?
Yes, there are already exploit tools available for both CVE-2024-40725 and CVE-2024-40898. Proof-of-concept (PoC) exploit codes have been published on GitHub. These tools demonstrate how the vulnerabilities can be exploited by sending specially crafted HTTP or SSL requests to affected Apache HTTP Server versions 2.4.0 through 2.4.61.

Has this vulnerability already been used in an attack?
There have been no reported instances of CVE-2024-40725 or CVE-2024-40898 being actively exploited in real-world attacks. However, given the availability of proof-of-concept (PoC) exploit codes, it’s crucial to apply the recommended patches and review your server configurations to mitigate these risks.

Are hackers discussing this vulnerability in the Deep/Dark Web?
Hackers are actively discussing the CVE-2024-40725 and CVE-2024-40898 vulnerabilities on the Deep/Dark Web.

What is the attack complexity level?
The attack complexity level for CVE-2024-40725 and CVE-2024-40898 in the Apache HTTP server is assessed as High.

EXPLOIT AND ANALYSIS

Our analysis has identified over 7.6 million internet-exposed instances of the Apache HTTP Server vulnerable to CVE-2024-40725 and CVE-2024-40898. CVE-2024-40725 enables HTTP Request Smuggling attacks, which can result in unauthorized access, data exposure, and session hijacking, potentially leading to data theft or manipulation. Meanwhile, CVE-2024-40898 involves an authentication bypass, allowing unauthorized system access, exposing sensitive information, and increasing the risk of further exploitation, including privilege escalation or additional attacks.

CVE-2024-40725: HTTP Request Smuggling

Script Overview: The Python script for detecting CVE-2024-40725 tests for HTTP Request Smuggling vulnerabilities in the Apache HTTP Server. It constructs a malicious HTTP request designed to exploit the vulnerability by using chunked transfer encoding. The script sends this crafted request to the target server and checks the response to determine if the attack was successful.

Functionality:

• Request Construction: The script creates a POST request with chunked encoding and a smuggled GET request targeting an admin endpoint.
• Response Analysis: If the server responds with a status code of 200 and includes “admin” in the response text, the server may be vulnerable to HTTP Request Smuggling.

Potential Exploits:

• Unauthorized Access: Attackers may gain access to restricted areas or perform unauthorized actions.
• Information Disclosure: Sensitive information could be exposed.
• Session Hijacking: Attackers might hijack user sessions, leading to data theft or manipulation.

CVE-2024-40898: SSL Verification Bypass

Script Overview: The Python script for detecting CVE-2024-40898 checks for SSL verification bypass vulnerabilities. It uses the SSL and socket modules to establish a secure connection with the target server, configured to allow optional client authentication. The script sends a basic HTTP request to the server and examines the response to identify potential bypasses.

Functionality:

• SSL Configuration: The script sets up an SSL context with ssl.CERT_OPTIONAL and wraps the socket to communicate securely with the target server.
• Response Analysis: If the server responds with “200 OK”, it may indicate that SSL verification is improperly configured, potentially allowing an authentication bypass.

Potential Exploits:

• Unauthorized System Access: Attackers could gain access to systems without proper authentication.
• Sensitive Information Exposure: Unauthorized users might access critical data.
• Further Exploits: Once inside, attackers might exploit other vulnerabilities or escalate privileges.

MITIGATION

To mitigate the risks associated with CVE-2024-40725 and CVE-2024-40898, immediately upgrade to the Apache HTTP Server version 2.4.62 or later. Review and secure your ProxyPass and URL rewrite configurations to prevent HTTP Request Smuggling and adjust the SSLVerifyClient settings to enforce proper client certificate authentication. Additionally, deploy a Web Application Firewall (WAF), enhance monitoring and logging, and conduct regular security assessments to safeguard against these vulnerabilities and future threats.

EXTERNAL THREAT LANDSCAPE MANAGEMENT

Target Geography:
The vulnerabilities CVE-2024-40725 and CVE-2024-40898 in the Apache HTTP Server pose a significant threat across multiple regions, including the United States, Germany, India, the Netherlands, and the United Kingdom. HTTP Request Smuggling attacks associated with CVE-2024-40725 can lead to unauthorized access, information disclosure, and session hijacking, affecting organizations globally. CVE-2024-40898 can facilitate authentication bypass, further exacerbating risks. Given the widespread exposure and impact, it is crucial for organizations in these regions to prioritize patching and enhance their security measures to protect against potential exploitation.

Target Industry:
The CVE-2024-40725 and CVE-2024-40898 vulnerabilities in Apache’s HTTP Server impact a wide range of industries, including financial services, healthcare, retail, government, and technology. These sectors face significant risks, such as unauthorized access, data breaches, and session hijacking. To mitigate these threats, organizations in these industries must prioritize timely patching, strengthen security controls, and enhance monitoring to protect against potential exploitation.

Target Technology:
The impact extends to various technological environments, including web hosting services, content management systems, and application delivery platforms. Organizations leveraging Apache’s HTTP Server for web and application hosting are particularly vulnerable to these issues. It is essential for technology providers and users to promptly apply security patches, review configurations, and implement additional security measures to safeguard against the exploitation of these vulnerabilities.

UNDERGROUND AND DARK WEB FORUMS

In underground forums, threat actors are actively focusing on the exploitation of the recently discovered CVE-2024-40725 and CVE-2024-40898 vulnerabilities. Malicious actors are sharing and analyzing exploits related to this vulnerability, including technical details and potential impacts of associated proof-of-concepts (PoCs). This level of attention highlights the serious concern within the cybercriminal community about the severity and potential consequences of this vulnerability.

CONCLUSION

The vulnerabilities CVE-2024-40725 and CVE-2024-40898 present severe risks to Apache’s HTTP Server installations, with over 7.6 million instances exposed on the internet. CVE-2024-40725 facilitates HTTP Request Smuggling attacks that can lead to unauthorized access, data exposure, and session hijacking, potentially resulting in significant data theft or manipulation. CVE-2024-40898 allows for authentication bypass, which can grant unauthorized access to systems, expose sensitive information, and enable further exploitation, including privilege escalation. Immediate patching and comprehensive security measures are essential to mitigate these risks and safeguard critical systems and data from potential breaches.