CVE-2005-1061 in Red Hat
Summary
by MITRE
The secure script in LogWatch before 2.6-2 allows attackers to prevent LogWatch from detecting malicious activity via certain strings in the secure file that are later used as part of a regular expression, which causes the parser to crash, aka "logwatch log processing regular expression DoS."
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Analysis
by VulDB Data Team • 07/04/2025
The vulnerability identified as CVE-2005-1061 represents a significant denial of service weakness in the LogWatch log analysis tool prior to version 2.6-2. This flaw specifically targets the secure script component of LogWatch, which is designed to process and analyze system logs for security monitoring purposes. The vulnerability arises from insufficient input validation and sanitization within the regular expression processing mechanism that LogWatch employs to parse log entries. When malicious actors craft specially formatted strings within the secure file, these inputs can be inadvertently processed as part of regular expression patterns, leading to catastrophic failures in the log processing pipeline.
The technical implementation of this vulnerability stems from the insecure handling of user-supplied data within the regular expression engine of LogWatch. The secure script processes entries from the secure file and uses these entries as components within regular expressions for log parsing operations. When these strings contain metacharacters or special regex syntax, they can cause the regular expression engine to enter infinite loops, excessive backtracking, or consume excessive computational resources. This behavior aligns with common weakness patterns documented in CWE-185, which addresses improper handling of regular expression special characters, and CWE-400, which covers unspecified denial of service conditions. The vulnerability essentially allows attackers to craft input that triggers resource exhaustion in the regular expression processor, causing the entire LogWatch system to become unresponsive or crash entirely.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the integrity of security monitoring operations. When LogWatch fails to process logs due to this denial of service condition, organizations lose visibility into their system activities, creating blind spots in their security infrastructure. This is particularly concerning in environments where LogWatch serves as a critical component for detecting malicious activity, as attackers can exploit this weakness to evade detection by preventing the system from analyzing potentially suspicious log entries. The vulnerability creates a scenario where the very tool designed to protect against malicious activity becomes a vector for disabling that protection, making it a particularly dangerous weakness in security monitoring frameworks.
Mitigation strategies for this vulnerability require a multi-layered approach focusing on input validation, regular expression sanitization, and system hardening. Organizations should immediately upgrade to LogWatch version 2.6-2 or later, which includes proper input sanitization and regular expression handling mechanisms. The solution involves implementing strict validation of input strings before they are incorporated into regular expression patterns, including escaping special regex characters and implementing timeouts for regex processing operations. Security practitioners should also consider implementing monitoring for unusual resource consumption patterns in log processing systems and establishing fallback mechanisms for log analysis when primary systems fail. This vulnerability demonstrates the importance of applying the principle of least privilege and input sanitization in security tools, as documented in the ATT&CK framework under techniques related to privilege escalation and evasion through service disruption. Organizations should also implement regular security assessments of log management systems to identify similar vulnerabilities that could be exploited to compromise security monitoring capabilities.