CVE-2005-1527 in awstats
Summary
by MITRE
Eval injection vulnerability in awstats.pl in AWStats 6.4 and earlier, when a URLPlugin is enabled, allows remote attackers to execute arbitrary Perl code via the HTTP Referrer, which is used in a $url parameter that is inserted into an eval function call.
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Analysis
by VulDB Data Team • 07/02/2025
The CVE-2005-1527 vulnerability represents a critical server-side code injection flaw in the AWStats web analytics tool version 6.4 and earlier. This vulnerability specifically affects systems where the URLPlugin functionality is enabled, creating a dangerous attack vector that allows remote adversaries to execute arbitrary Perl code on the affected server. The flaw stems from improper input validation and sanitization within the awstats.pl script, which processes HTTP referrer data without adequate security measures. When a malicious HTTP referrer is sent to the server, the application incorporates this data directly into a $url parameter that is subsequently passed to an eval function call, thereby enabling arbitrary code execution.
The technical exploitation of this vulnerability follows a well-defined pattern that aligns with common web application injection attack methodologies. Attackers craft malicious HTTP referrer headers containing Perl code that gets processed by the vulnerable eval function, effectively bypassing normal application security controls. This type of vulnerability falls under the CWE-94 category of "Improper Control of Generation of Code" and specifically relates to CWE-74 which addresses "Improper Neutralization of Special Elements in Output Used by a Downstream Component." The attack vector operates through the HTTP protocol and leverages the trust relationship between the web server and the analytics tool, making it particularly dangerous as it can be exploited without requiring authentication or direct access to the system.
The operational impact of CVE-2005-1527 extends far beyond simple data theft or service disruption. Successful exploitation can result in complete system compromise, allowing attackers to execute commands with the privileges of the web server process, potentially leading to full network infiltration. The vulnerability affects web servers running AWStats with URLPlugin enabled, which could include any system that processes web traffic logs for analytics purposes. This creates a wide attack surface as many organizations rely on web analytics tools for monitoring and reporting. The attack can be performed remotely without user interaction, making it particularly dangerous for systems with public-facing web servers. From an operational security perspective, this vulnerability can be exploited to establish persistent backdoors, exfiltrate sensitive data, or use the compromised server as a launch point for further attacks within the network infrastructure.
Mitigation strategies for CVE-2005-1527 should focus on immediate patching of the AWStats application to version 6.5 or later, where the vulnerability has been addressed through proper input validation and sanitization. Organizations should disable the URLPlugin functionality if it is not essential for their analytics requirements, as this removes the attack surface entirely. Network-level defenses should include implementing web application firewalls that can detect and block malicious referrer headers containing suspicious Perl code patterns. Additionally, system administrators should review and restrict the privileges of the web server process to minimize potential damage from successful exploitation attempts. The remediation process should also involve monitoring network traffic for unusual referrer patterns and implementing proper logging mechanisms to detect exploitation attempts. Security teams should consider this vulnerability as part of a broader threat landscape and ensure that similar code injection vulnerabilities are addressed in other applications through proper input validation and output encoding practices. This vulnerability serves as a reminder of the critical importance of secure coding practices and regular security updates in preventing remote code execution attacks.