CVE-2024-7634 in NGINX Agent
Summary
by MITRE • 08/22/2024
NGINX Agent's "config_dirs" restriction feature allows a highly privileged attacker to gain the ability to write/overwrite files outside of the designated secure directory.
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Analysis
by VulDB Data Team • 08/24/2024
The vulnerability identified as CVE-2024-7634 affects the NGINX Agent's configuration directory restriction mechanism, presenting a critical security flaw that undermines the intended security boundaries of the system. This issue resides within the agent's implementation of the "config_dirs" restriction feature, which is designed to limit file system access to specific directories while maintaining operational integrity. The flaw allows an attacker with elevated privileges to bypass these restrictions and gain unauthorized write access to arbitrary locations within the file system, effectively compromising the agent's security model and potentially enabling broader system compromise.
The technical implementation of this vulnerability stems from improper input validation and path traversal handling within the NGINX Agent's configuration management subsystem. When the agent processes configuration files or directory specifications, it fails to adequately sanitize user-supplied directory paths or configuration parameters that may contain malicious traversal sequences. This weakness creates a path traversal condition where attacker-controlled input can manipulate the agent's file system operations to target locations outside the intended secure directories. The flaw operates at the intersection of inadequate access control enforcement and insufficient path normalization, allowing privilege escalation through configuration file manipulation.
The operational impact of CVE-2024-7634 extends beyond simple file system access violations and represents a significant threat to system integrity and confidentiality. A highly privileged attacker who can exploit this vulnerability can overwrite critical system files, inject malicious code into running processes, or manipulate configuration data to establish persistent access points. The attack surface is particularly concerning given that the NGINX Agent typically runs with elevated privileges to manage web server configurations, making the compromise of its restriction mechanisms equivalent to gaining elevated access to the underlying system. This vulnerability directly maps to CWE-22 Path Traversal and CWE-73 Path Traversal, both of which are classified as high-risk weaknesses in the Common Weakness Enumeration catalog.
Security implications of this vulnerability align with several tactics and techniques documented in the MITRE ATT&CK framework, particularly those related to privilege escalation and persistence. The ability to write files outside designated directories enables attackers to establish backdoors, modify system binaries, or manipulate configuration files that could be loaded by other system components. The exploitation process typically involves crafting malicious configuration parameters that leverage the agent's legitimate file system access capabilities to achieve unauthorized modifications. Organizations using NGINX Agent in production environments face heightened risk of supply chain attacks or insider threats where compromised privileged accounts can leverage this vulnerability to achieve system-wide compromise.
Mitigation strategies for CVE-2024-7634 require immediate implementation of several defensive measures including updating to patched versions of the NGINX Agent, implementing additional access controls through operating system level restrictions, and monitoring for unauthorized file system modifications. System administrators should conduct comprehensive audits of all NGINX Agent configurations to identify and remediate any potentially compromised installations. The vulnerability highlights the importance of proper input validation and the principle of least privilege in security design, emphasizing that even privileged applications must enforce strict boundaries on their file system operations. Organizations should also implement monitoring solutions that can detect anomalous file system access patterns or unauthorized write operations to the system directories, providing early warning capabilities against exploitation attempts.