CVE-2008-1570 in policyd-weight
Summary
by MITRE
Race condition in the create_lockpath function in policyd-weight 0.1.14 beta-16 allows local users to modify or delete arbitrary files by creating the LOCKPATH directory, then modifying it after the symbolic link check occurs. NOTE: this is due to an incomplete fix for CVE-2008-1569.
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Analysis
by VulDB Data Team • 07/31/2021
The vulnerability described in CVE-2008-1570 represents a race condition flaw within the policyd-weight mail filtering system version 0.1.14 beta-16. This issue specifically manifests in the create_lockpath function where improper synchronization allows local attackers to exploit timing windows in the system's file access controls. The vulnerability arises from an incomplete remediation of a previously identified flaw, CVE-2008-1569, which demonstrates the complexity of addressing security issues in software systems where fixes may inadvertently introduce new attack vectors.
The technical implementation of this race condition occurs when the system attempts to create a LOCKPATH directory structure while simultaneously checking for symbolic link conditions. During this brief window between the initial directory creation and the symbolic link validation, a malicious local user can manipulate the filesystem by creating their own directory structure that will be targeted by the subsequent operations. This timing discrepancy enables attackers to bypass intended security controls and potentially modify or delete files that should remain protected. The flaw operates at the filesystem level and exploits the fundamental timing issues inherent in concurrent access scenarios.
From an operational impact perspective, this vulnerability poses significant risks to mail server security infrastructure that relies on policyd-weight for content filtering and policy enforcement. Local users who can execute code on the system gain the ability to manipulate critical system files, potentially leading to privilege escalation, data corruption, or complete system compromise. The attack requires local system access but does not need network connectivity, making it particularly dangerous in environments where local privilege escalation is possible. The vulnerability affects systems where policyd-weight is deployed as a mail filtering service, potentially compromising email delivery policies and security controls.
The mitigation strategy for this vulnerability requires immediate patching of the policyd-weight software to address the race condition properly. System administrators should upgrade to versions that contain a complete fix for the issue, ensuring that the directory creation and symbolic link validation processes are properly synchronized. Additionally, implementing proper file access controls and monitoring for unauthorized filesystem modifications can help detect potential exploitation attempts. The vulnerability aligns with CWE-367, which addresses time-of-check to time-of-use (TOCTOU) flaws, and maps to ATT&CK technique T1059 for privilege escalation through local system manipulation. Organizations should also consider implementing least privilege principles and regular security audits to prevent unauthorized local access that could enable exploitation of such timing-based vulnerabilities.