CVE-2003-0084 in Linux
Summary
by MITRE
mod_auth_any package in Red Hat Enterprise Linux 2.1 and other operating systems does not properly escape arguments when calling other programs, which allows attackers to execute arbitrary commands via shell metacharacters.
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Analysis
by VulDB Data Team • 08/25/2025
The vulnerability described in CVE-2003-0084 represents a critical command injection flaw within the mod_auth_any Apache module used in Red Hat Enterprise Linux 2.1 and similar operating systems. This security weakness stems from improper input sanitization when the module processes authentication arguments and passes them to underlying system commands. The flaw occurs during the authentication process where user-provided credentials or parameters are not adequately escaped before being executed in shell contexts, creating an avenue for malicious exploitation.
The technical implementation of this vulnerability resides in the mod_auth_any module's failure to properly handle shell metacharacters within authentication arguments. When legitimate authentication requests are processed, the module constructs command strings by concatenating user inputs without appropriate shell escaping mechanisms. This design flaw allows attackers to inject shell commands through specially crafted authentication parameters that contain metacharacters such as semicolons, ampersands, or backticks. The vulnerability directly maps to CWE-78, which specifically addresses improper neutralization of special elements used in OS commands, making it a classic example of command injection vulnerability.
The operational impact of this vulnerability is severe and potentially catastrophic for affected systems. An attacker who successfully exploits this flaw can execute arbitrary commands with the privileges of the Apache web server process, typically running as the root user or a high-privilege account. This level of access enables complete system compromise including data exfiltration, privilege escalation, installation of backdoors, and further lateral movement within the network. The vulnerability affects not only the targeted web server but also potentially exposes the entire underlying infrastructure to unauthorized access and control.
Organizations should implement multiple layers of defense to mitigate this vulnerability effectively. Immediate remediation involves applying the vendor patches provided by Red Hat for their Enterprise Linux 2.1 systems and upgrading to supported versions where this vulnerability has been addressed. System administrators should also implement input validation and sanitization measures at the web server level to prevent malicious characters from reaching the authentication modules. Network segmentation and firewall rules can help limit the attack surface, while monitoring solutions should be configured to detect unusual command execution patterns. According to ATT&CK framework, this vulnerability maps to T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, making it a critical target for both defensive and offensive security operations. Regular security assessments and penetration testing should be conducted to identify similar input validation weaknesses in other components of the web application stack, as this type of vulnerability often indicates broader architectural issues in application security design.