CVE-2013-4481 in Red Hat
Summary
by MITRE
Race condition in Luci 0.26.0 creates /var/lib/luci/etc/luci.ini with world-readable permissions before restricting the permissions, which allows local users to read the file and obtain sensitive information such as "authentication secrets."
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Analysis
by VulDB Data Team • 01/10/2022
The vulnerability identified as CVE-2013-4481 represents a critical race condition flaw within the Luci web interface version 0.26.0 that compromises system security through improper file permission handling. This issue affects the configuration management process where the application creates sensitive configuration files without adequate access controls, creating a window of opportunity for local privilege escalation and information disclosure attacks. The flaw manifests during the initialization sequence when Luci generates its configuration file at /var/lib/luci/etc/luci.ini before applying restrictive permissions, leaving the file temporarily accessible to all system users.
The technical implementation of this vulnerability stems from a fundamental timing issue in the file creation and permission setting process. When Luci initializes its configuration environment, it first creates the luci.ini file with default permissions that grant read access to all users on the system. Only after this initial creation process does the application attempt to restrict access permissions to prevent unauthorized reading of the sensitive data contained within. This temporal gap between file creation and permission restriction creates a race condition that malicious local users can exploit to read the configuration file before access controls are properly enforced. The file contains authentication secrets and other sensitive information that could be leveraged for further system compromise.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks. Local users who can read the luci.ini file gain access to authentication credentials that may be used to impersonate legitimate users or escalate privileges within the system. The exposure of authentication secrets in this context aligns with CWE-200, which addresses the improper exposure of sensitive information, and represents a significant weakening of the system's security posture. Attackers could utilize this information to gain unauthorized access to services managed by Luci or to conduct privilege escalation attacks against the local system.
Security professionals should recognize this vulnerability as a classic example of improper privilege management and timing-related security flaws that are commonly addressed through proper initialization sequencing and access control enforcement. The issue demonstrates the importance of implementing defense-in-depth strategies where access controls are established before sensitive data is written to persistent storage. Mitigation strategies should include updating to patched versions of Luci that properly implement file permission handling during initialization, implementing proper file access control mechanisms, and conducting regular security audits to identify similar race conditions in other system components. Organizations should also consider implementing monitoring solutions that can detect unauthorized access attempts to sensitive configuration files, as outlined in the attack patterns documented in the MITRE ATT&CK framework under privilege escalation and credential access categories. The vulnerability serves as a reminder of the critical importance of proper file permission management and the potential consequences of inadequate access control implementation in system initialization processes.