CVE-2011-1018 in logwatch
Summary
by MITRE
logwatch.pl in Logwatch 7.3.6 allows remote attackers to execute arbitrary commands via shell metacharacters in a log file name, as demonstrated via a crafted username to a Samba server.
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Analysis
by VulDB Data Team • 01/15/2025
The vulnerability identified as CVE-2011-1018 represents a critical command injection flaw within the logwatch.pl script component of Logwatch version 7.3.6. This issue arises from insufficient input validation and sanitization mechanisms that fail to properly escape or filter special shell metacharacters present in log file names. The vulnerability specifically manifests when Logwatch processes log files that contain maliciously crafted usernames or file paths, particularly in environments where Samba servers are utilized for file sharing and authentication services. The flaw operates at the intersection of log processing and shell command execution, creating a pathway for remote attackers to escalate privileges and execute arbitrary code on the affected system. This represents a classic example of a command injection vulnerability that can be exploited through indirect means, leveraging the legitimate log processing functionality to bypass normal security controls.
The technical exploitation of this vulnerability occurs when a malicious actor crafts a Samba username or log file name containing shell metacharacters such as semicolons, ampersands, or backticks that get interpreted by the underlying shell when Logwatch attempts to process the log data. The logwatch.pl script, which is designed to parse and analyze system logs for security monitoring purposes, fails to properly sanitize user-provided input before incorporating it into shell commands. This allows attackers to inject malicious commands that execute with the privileges of the user running the Logwatch process, typically a system administrator or service account with elevated permissions. The vulnerability falls under the CWE-78 category of Improper Neutralization of Special Elements used in an OS Command, which is a well-documented weakness in software systems that handle user input through shell operations. The attack vector is particularly insidious because it leverages legitimate system logging functionality to deliver malicious payloads, making it difficult to detect through traditional security monitoring approaches.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as successful exploitation can result in complete system compromise and persistent access for attackers. When an attacker successfully executes arbitrary commands through this vulnerability, they gain the ability to manipulate system files, install backdoors, exfiltrate sensitive data, or establish persistent access through various attack techniques documented in the MITRE ATT&CK framework under the T1059.001 technique for command and scripting interpreter. The vulnerability affects systems that rely on Logwatch for security monitoring, particularly those with Samba services configured to log user activities, as these environments provide the most direct attack surface for exploitation. Organizations running vulnerable versions of Logwatch may experience unauthorized access to their network infrastructure, with potential for lateral movement and privilege escalation throughout the enterprise environment. The impact is compounded by the fact that Logwatch is commonly used for security auditing and monitoring, meaning that exploitation could go undetected for extended periods while attackers maintain persistent access to the compromised systems.
Mitigation strategies for CVE-2011-1018 require immediate patching of the Logwatch software to version 7.3.7 or later, which includes proper input sanitization and shell metacharacter escaping mechanisms. System administrators should also implement strict input validation on all log file names and user credentials entering the system, particularly in Samba environments where this vulnerability is most prevalent. Network segmentation and privilege separation practices should be enforced to limit the potential impact of successful exploitation, ensuring that Logwatch processes run with minimal necessary permissions. Additional defensive measures include implementing proper log monitoring and alerting systems that can detect unusual command execution patterns, as well as conducting regular security audits of logging and monitoring configurations. Organizations should also consider implementing web application firewalls or security monitoring solutions that can detect and block suspicious shell command injection attempts, aligning with ATT&CK techniques for detection and prevention. The vulnerability highlights the critical importance of proper input validation and output encoding in security-sensitive applications, particularly those that interface with system-level operations and shell commands.