CVE-2011-1098 in logrotate
Summary
by MITRE
Race condition in the createOutputFile function in logrotate.c in logrotate 3.7.9 and earlier allows local users to read log data by opening a file before the intended permissions are in place.
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Analysis
by VulDB Data Team • 10/21/2021
The vulnerability described in CVE-2011-1098 represents a classic race condition flaw within the logrotate utility that has significant implications for system security and data confidentiality. This issue affects logrotate versions 3.7.9 and earlier, where the createOutputFile function contains a timing window that allows local attackers to exploit the system's file creation process. The fundamental problem arises from the lack of proper synchronization mechanisms during the file creation and permission setting phases, creating an exploitable gap in the security model.
The technical implementation of this race condition occurs within the logrotate.c source file where the createOutputFile function handles the creation of new log output files. During the normal operation of logrotate, when a log file needs to be rotated, the system creates a new output file and then applies the appropriate permissions to it. However, there exists a temporal window between the file creation and the application of restrictive permissions where the file becomes accessible to unauthorized users. This window is typically very brief but sufficient for a local attacker to open and read the file contents before proper access controls are enforced. The vulnerability specifically targets the atomicity of file operations, where the separation between file creation and permission assignment creates a security boundary that can be exploited.
The operational impact of this vulnerability extends beyond simple information disclosure, as it represents a privilege escalation vector that can be leveraged by local attackers to access sensitive log data that may contain authentication credentials, system information, or other confidential operational details. The race condition allows attackers to potentially read log files that contain passwords, session tokens, or other sensitive information that should normally be restricted to authorized users. This vulnerability is particularly concerning in multi-user environments where different users may have varying levels of access to system logs. The impact is amplified when considering that logrotate is a widely used system utility that typically runs with elevated privileges, making this vulnerability a potential gateway for further compromise. The exploitation of this vulnerability can lead to information leakage that may aid in subsequent attacks, including credential harvesting and system reconnaissance activities.
Mitigation strategies for this vulnerability should focus on both immediate patching and operational hardening measures. The most effective solution involves upgrading to logrotate version 3.8.0 or later, where the race condition has been addressed through proper synchronization mechanisms and atomic file creation operations. System administrators should also implement monitoring for unauthorized file access attempts and consider implementing additional security controls such as proper file permission management and regular security audits. The vulnerability aligns with CWE-362, which describes a race condition flaw in software design, and can be categorized under ATT&CK technique T1070.006 for indicator removal on systems, as attackers may attempt to cover their tracks by reading sensitive log data. Additionally, this vulnerability demonstrates the importance of following secure coding practices and proper file handling procedures, particularly when dealing with system utilities that manage sensitive data and require elevated privileges to operate. Organizations should also consider implementing automated patch management systems to ensure timely deployment of security fixes and maintain comprehensive logging of system activities to detect potential exploitation attempts.