Critical Apache HTTP Server Vulnerability CVE-2024-38474: Immediate Update Recommended

Executive Summary

CVE-2024-38474 is a critical vulnerability affecting the Apache HTTP Server, specifically versions 2.4.59 and earlier. This vulnerability, rooted in the

mod_rewrite

module, allows unauthorized script execution in directories that are permitted by configuration but not directly accessible via URL. With a CVSS v3.1 Base Score of 9.8, this vulnerability poses a severe risk to confidentiality, integrity, and availability. Although there are no current reports of exploitation in the wild, the potential impact necessitates immediate attention and remediation.

Technical Information

The vulnerability CVE-2024-38474 is a result of a substitution encoding issue within the

mod_rewrite

module of the Apache HTTP Server. This flaw permits attackers to execute scripts in directories that are configured to allow such actions, even if these directories are not directly reachable by any URL. The vulnerability is classified as critical due to its low attack complexity, requiring no privileges or user interaction, and its potential to significantly impact system confidentiality, integrity, and availability.

The

mod_rewrite

module is a powerful tool used to manipulate URLs based on server-side rules. However, the substitution encoding issue in this module can be exploited to bypass security restrictions, leading to unauthorized script execution. This can result in the disclosure of sensitive information, unauthorized access, and potential system compromise.

The vulnerability affects Apache HTTP Server versions 2.4.59 and earlier. The issue arises when unsafe

RewriteRules

are configured, allowing attackers to execute scripts in unintended directories. The critical nature of this vulnerability is underscored by its high CVSS score, indicating the potential for widespread impact if exploited.

Organizations using affected versions of the Apache HTTP Server are advised to upgrade to version 2.4.60 or later, which addresses this vulnerability. The update ensures that unsafe

RewriteRules

will fail unless the "UnsafeAllow3F" flag is specified. Additionally, administrators should review and update their

mod_rewrite

configurations to prevent inadvertent script execution.

Exploitation in the Wild

As of now, there are no confirmed reports of CVE-2024-38474 being exploited in the wild. Furthermore, no known exploits have been developed for this vulnerability. However, given the critical nature of the issue, organizations should remain vigilant and take proactive measures to secure their systems. Monitoring for signs of exploitation and applying security patches promptly are essential steps in mitigating potential risks.

APT Groups using this vulnerability

While specific APT groups exploiting CVE-2024-38474 have not been identified, it is important to note that groups known for targeting web server vulnerabilities, such as APT28 and APT41, may potentially exploit similar vulnerabilities. These groups have a history of targeting sectors across various countries, including government, finance, and technology, making it crucial for organizations in these sectors to prioritize security measures.

Affected Product Versions

The vulnerability affects Apache HTTP Server versions 2.4.59 and earlier. Organizations using these versions are at risk and should take immediate action to upgrade to a secure version. The latest version, 2.4.60, addresses the vulnerability and provides enhanced security measures to prevent unauthorized script execution.

Workaround and Mitigation

To mitigate the risks associated with CVE-2024-38474, organizations should upgrade their Apache HTTP Server to version 2.4.60 or later. This update addresses the vulnerability by ensuring that unsafe

RewriteRules

will fail unless the "UnsafeAllow3F" flag is specified. Additionally, administrators should review and update their

mod_rewrite

configurations to prevent inadvertent script execution. Regular monitoring of systems for signs of exploitation and prompt application of security patches are also recommended to mitigate potential risks.

References

For more information on CVE-2024-38474, please refer to the following resources:

• SUSE Security Advisory on CVE-2024-38474: https://www.suse.com/security/cve/CVE-2024-38474.html
• Debricked Vulnerability Database: https://debricked.com/vulnerability-database/vulnerability/CVE-2024-38474
• Apache HTTP Server Security Vulnerabilities: https://httpd.apache.org/security/vulnerabilities_24.html

Rescana is here for you

At Rescana, we are committed to helping our customers navigate the complex landscape of cybersecurity threats. Our Continuous Threat and Exposure Management (CTEM) platform provides comprehensive solutions to identify, assess, and mitigate vulnerabilities, ensuring the security and resilience of your systems. If you have any questions about this report or any other cybersecurity concerns, please do not hesitate to contact us at ops@rescana.com. We are here to support you in safeguarding your organization's digital assets.