CVE-2002-0374 in PAM LDAP
Summary
by MITRE
Format string vulnerability in the logging function for the pam_ldap PAM LDAP module before version 144 allows attackers to execute arbitrary code via format strings in the configuration file name.
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Analysis
by VulDB Data Team • 09/13/2025
The vulnerability identified as CVE-2002-0374 represents a critical format string flaw within the pam_ldap PAM module, specifically affecting versions prior to 144. This issue resides in the logging function implementation where the module fails to properly sanitize user-supplied input before using it in format string operations. The vulnerability manifests when the module processes configuration file names that contain format specifiers, allowing malicious actors to inject arbitrary format string sequences that can be exploited to execute code with elevated privileges. The flaw occurs because the logging function directly incorporates user-provided configuration parameters without proper validation or escaping, creating a path for attackers to manipulate memory contents through format string exploitation techniques.
The technical exploitation of this vulnerability follows established patterns described in CWE-134, which categorizes format string vulnerabilities as weaknesses in software that allows attackers to control format strings passed to functions like printf or fprintf. In this specific case, when the pam_ldap module encounters a configuration file name containing malicious format specifiers such as %x or %s, these sequences can be interpreted by the logging function to read arbitrary memory locations or write data to specific addresses. Attackers can leverage this to overwrite function pointers, inject shellcode, or manipulate program flow to achieve arbitrary code execution. The vulnerability is particularly dangerous because it operates within the PAM framework, which handles authentication and authorization processes, meaning successful exploitation could provide attackers with elevated system privileges and access to sensitive authentication mechanisms.
The operational impact of CVE-2002-0374 extends beyond simple code execution to compromise the entire authentication infrastructure of systems relying on LDAP-based PAM modules. Since PAM modules are integral to system security controls, exploitation could lead to complete system compromise, unauthorized access to user accounts, and potential lateral movement within network environments. The vulnerability affects systems where pam_ldap is configured to log configuration file names or paths that might be influenced by user input, creating a significant attack surface for privilege escalation. This type of vulnerability aligns with ATT&CK technique T1068, which covers 'Local Privilege Escalation' through the exploitation of system vulnerabilities, and T1566, which addresses 'Phishing' through the manipulation of system components that handle user authentication.
Mitigation strategies for this vulnerability require immediate patching of the pam_ldap module to version 144 or later, where proper input sanitization and format string handling have been implemented. Organizations should also implement configuration hardening measures to prevent user-controllable inputs from reaching the logging functions, including validating and sanitizing all configuration file names before processing. The solution aligns with security best practices outlined in NIST SP 800-128 and ISO 27001 controls for input validation and secure coding practices. Additionally, system administrators should conduct comprehensive audits of all PAM module configurations to identify potential attack vectors and implement monitoring for suspicious log entries that might indicate exploitation attempts. Network segmentation and privilege separation should be enforced to limit the potential damage from successful exploitation, while regular security assessments should verify that no other modules within the authentication framework contain similar format string vulnerabilities.