CVE-2014-4703 in Nagios
Summary
by MITRE
lib/parse_ini.c in Nagios Plugins 2.0.2 allows local users to obtain sensitive information via a symlink attack on the configuration file in the extra-opts flag. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-4701.
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Analysis
by VulDB Data Team • 11/26/2024
The vulnerability described in CVE-2014-4703 represents a critical security flaw in the Nagios Plugins 2.0.2 software suite, specifically within the lib/parse_ini.c component. This issue manifests as a symlink attack vulnerability that enables local attackers to access sensitive configuration data through improper handling of the extra-opts flag parameter. The vulnerability is particularly concerning because it builds upon and fails to fully address the previously identified CVE-2014-4701, indicating a pattern of incomplete security remediation that leaves systems exposed to persistent threats. The root cause lies in the insufficient validation of symbolic link references when processing configuration files, creating an attack vector that can be exploited by users with local access to the system.
The technical implementation of this vulnerability occurs when the Nagios Plugins software processes command-line arguments containing the extra-opts flag, which is designed to accept additional configuration parameters. During this processing, the software does not properly validate whether the specified configuration file path points to a symbolic link, allowing malicious actors to create a symbolic link that points to sensitive system files such as /etc/shadow or other critical configuration data. When the parsing function encounters the symlink, it follows the link and attempts to read the target file, thereby exposing confidential information that should remain protected. This behavior directly violates security principles outlined in CWE-59, which addresses improper handling of symbolic links, and demonstrates a failure to implement proper path validation mechanisms.
From an operational perspective, this vulnerability significantly impacts system security posture by providing local attackers with unauthorized access to sensitive information that could be used for privilege escalation or further system compromise. The attack requires only local system access, making it particularly dangerous in multi-user environments where attackers might exploit this vulnerability to gain insights into system configurations, user accounts, or authentication mechanisms. The exposure of sensitive configuration data through this symlink attack can lead to cascading security issues, including potential credential theft, service disruption, or unauthorized access to network resources. This vulnerability aligns with ATT&CK technique T1005, which covers data from local system, and T1059, which addresses command and scripting interpreter, as attackers can leverage the exposed information to craft more sophisticated attacks.
The remediation approach for this vulnerability requires immediate patching of the Nagios Plugins software to implement proper symlink validation and resolution mechanisms. Organizations should ensure that all symbolic link references are properly resolved and validated before processing configuration files, implementing checks that prevent traversal to sensitive system locations. Security measures should include disabling the extra-opts flag when not required, implementing proper file access controls, and conducting regular security audits of configuration file handling processes. Additionally, system administrators should monitor for any unauthorized symbolic link creation in directories where Nagios plugins operate, as part of broader security monitoring practices. The vulnerability serves as a reminder of the importance of complete security fixes and proper validation of file system operations, particularly in security-critical applications that handle sensitive configuration data.