CVE-2014-2583 in Linux-PAM
Summary
by MITRE
Multiple directory traversal vulnerabilities in pam_timestamp.c in the pam_timestamp module for Linux-PAM (aka pam) 1.1.8 allow local users to create arbitrary files or possibly bypass authentication via a .. (dot dot) in the (1) PAM_RUSER value to the get_ruser function or (2) PAM_TTY value to the check_tty function, which is used by the format_timestamp_name function.
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Analysis
by VulDB Data Team • 05/10/2026
The vulnerability identified as CVE-2014-2583 represents a critical directory traversal flaw within the Linux-PAM implementation specifically affecting the pam_timestamp module version 1.1.8. This security weakness resides in the pam_timestamp.c file and fundamentally compromises the integrity of the authentication framework by enabling unauthorized file system manipulation through crafted PAM environment variables. The vulnerability operates by exploiting improper input validation mechanisms within the module's handling of user and terminal identification parameters, creating opportunities for malicious actors to manipulate the timestamp file creation process.
The technical exploitation occurs through two distinct pathways that leverage the pam_timestamp module's insufficient sanitization of input parameters. The first vector involves manipulation of the PAM_RUSER value when passed to the get_ruser function, while the second involves manipulation of the PAM_TTY value when processed by the check_tty function. Both functions ultimately feed into the format_timestamp_name function which constructs file paths for timestamp storage without adequate validation of directory traversal sequences. This allows attackers to inject ".." sequences that can navigate outside the intended directory boundaries, potentially creating files in arbitrary locations or bypassing authentication mechanisms entirely.
From an operational perspective, this vulnerability presents a significant risk to system security as local users can leverage it to create malicious files in system directories or manipulate authentication timestamps to gain unauthorized access. The impact extends beyond simple file creation since the vulnerability can potentially be used to bypass authentication controls that rely on timestamp validation, effectively undermining the security model of the PAM framework. The flaw is particularly dangerous because it operates within the authentication subsystem itself, meaning that successful exploitation can provide attackers with elevated privileges or persistent access to the system.
The vulnerability maps to CWE-22 Directory Traversal and CWE-352 Cross-Site Request Forgery in the context of local privilege escalation, and aligns with ATT&CK techniques related to privilege escalation through credential access and persistence mechanisms. The attack surface is primarily local, requiring only user-level access to exploit, making it particularly concerning for environments where local accounts may be compromised. Organizations should consider implementing immediate mitigations such as updating to patched versions of Linux-PAM, applying restrictive file system permissions to timestamp directories, and monitoring for unauthorized file creation in sensitive system locations. Additionally, system administrators should review and tighten the configuration of PAM modules to minimize the attack surface and ensure that authentication components properly validate all input parameters before processing.