Critical Vulnerability in Apache HTTP Server: CVE-2024-38475
Recent developments in cybersecurity have highlighted a critical vulnerability, CVE-2024-38475, affecting the Apache HTTP Server. This vulnerability, which has been added to the Cybersecurity and Infrastructure Security Agency's (CISA) Known Exploited Vulnerabilities catalog, poses significant risks due to its potential for arbitrary code execution and source code disclosure. The flaw is rooted in the mod_rewrite module of Apache HTTP Server versions 2.4.59 and earlier, with a high CVSS score of 9.1, indicating its severity.
The vulnerability arises from improper escaping of output, allowing attackers to map URLs to unintended filesystem locations. This can lead to unauthorized access to sensitive system files, which are typically protected. The exploitation technique involves a filename confusion vulnerability that abuses the question mark (%3F) symbol to truncate the final constructed path, enabling attackers to bypass security measures.
CISA has mandated that organizations implement mitigations by May 22, 2025, under its binding operational directive. The agency emphasizes the urgency of addressing this vulnerability due to active exploitation across multiple sectors. Organizations are advised to upgrade to Apache HTTP Server version 2.4.60 or later and review affected RewriteRules to ensure substitutions are appropriately constrained.
Threats and Vulnerabilities
CVE-2024-38475 is a critical vulnerability in the Apache HTTP Server's mod_rewrite module, affecting versions 2.4.59 and earlier. It allows attackers to map URLs to filesystem locations that should not be accessible, potentially leading to arbitrary code execution or source code disclosure. The vulnerability exploits a filename confusion issue, leveraging the question mark (%3F) symbol to truncate paths and gain unauthorized access to sensitive files.
The impact of this vulnerability is significant, with a CVSS score of 9.1, indicating a high level of risk. It affects a common open-source component used by various products, making it a widespread concern across different industries. Active exploitation has been observed, underscoring the need for immediate remediation efforts.
Client Impact
Clients across various industries could face severe consequences if this vulnerability is exploited. Potential impacts include operational disruptions due to unauthorized access or code execution on critical systems. Data breaches or loss could occur if sensitive files are accessed or disclosed. Financial consequences may arise from remediation costs, legal liabilities, and potential fines for non-compliance with regulatory requirements.
Reputation damage is another significant risk, as clients may lose trust in organizations that fail to protect their systems adequately. Compliance implications are also critical; failure to address this vulnerability could lead to audits or penalties under regulations such as GDPR or CCPA.
Mitigations
To mitigate the risks associated with CVE-2024-38475, organizations should take the following actions:
- Upgrade to Apache HTTP Server version 2.4.60 or later to address the vulnerability.
- Review and modify affected RewriteRules to ensure substitutions are appropriately constrained if immediate patching isn’t possible.
- For SonicWall SMA users, immediately patch devices and review logs for unauthorized access.
- Implement micro-segmentation and zero-trust isolation projects to minimize potential lateral movement.
- Use the new rewrite flag “UnsafePrefixStat” in Apache configuration only after ensuring substitutions are appropriately constrained.
These steps aim to reduce the risk of exploitation and protect sensitive data from unauthorized access. Organizations should prioritize these actions based on their specific environment and threat landscape.
1898 & Co. Response
1898 & Co. is actively addressing the current threat landscape by offering specialized services and solutions tailored to mitigate emerging threats like CVE-2024-38475. Our team is focused on delivering thorough assessments and remediation strategies that align with industry standards and client needs.
We are updating our security protocols and practices to incorporate the latest threat intelligence and mitigation techniques. Our collaborative efforts with industry allies and government agencies enhance our ability to provide timely and effective responses to vulnerabilities.
Ongoing research and threat intelligence gathering activities are central to our approach, ensuring we remain at the forefront of cybersecurity developments. We provide clients with detailed insights and actionable recommendations based on real-world examples and case studies demonstrating successful mitigations.