CVE-2001-1290 in Active Classifieds
Summary
by MITRE
admin.cgi in Active Classifieds Free Edition 1.0, and possibly commercial versions, allows remote attackers to modify the configuration, gain privileges, and execute arbitrary Perl code via the table_width parameter.
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Analysis
by VulDB Data Team • 09/27/2025
The vulnerability identified as CVE-2001-1290 represents a critical security flaw in Active Classifieds Free Edition 1.0 and potentially its commercial counterparts. This issue resides within the admin.cgi script which serves as the administrative interface for managing classified advertisements. The vulnerability stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data before processing. Specifically, the table_width parameter within the administrative interface accepts unfiltered input that can be exploited by malicious actors to manipulate the application's configuration settings. This weakness creates a pathway for remote attackers to escalate their privileges and execute arbitrary Perl code on the affected system, fundamentally compromising the security posture of the web application.
The technical exploitation of this vulnerability follows a well-defined pattern that aligns with common web application attack vectors. Attackers can craft malicious payloads targeting the table_width parameter, bypassing normal input validation checks through techniques such as parameter manipulation or injection attacks. The flaw demonstrates characteristics consistent with CWE-20, which describes improper input validation, and CWE-74, covering injection flaws. When the vulnerable script processes the malicious input, it fails to properly escape or validate the table_width parameter, allowing attackers to inject and execute arbitrary Perl commands. This type of vulnerability is particularly dangerous because it enables complete system compromise through a single entry point, allowing attackers to modify application configuration files, escalate privileges, and potentially gain full control over the underlying server.
The operational impact of CVE-2001-1290 extends far beyond simple data manipulation, creating severe consequences for organizations relying on Active Classifieds systems. Remote code execution capabilities mean that attackers can establish persistent backdoors, exfiltrate sensitive data, or deploy additional malware without requiring physical access to the system. The privilege escalation aspect allows attackers to gain administrative access to the web application, potentially leading to complete compromise of the hosting environment. According to ATT&CK framework, this vulnerability maps to T1059.007 for command and scripting interpreter and T1068 for exploit for privilege escalation, demonstrating how the initial access can be leveraged for broader system compromise. Organizations using affected versions face significant risk of data breaches, service disruption, and potential regulatory violations due to the exposure of sensitive information and unauthorized system access.
Mitigation strategies for this vulnerability require immediate action to address the root cause through proper input validation and output encoding. System administrators should implement comprehensive input sanitization measures that validate and filter all user-supplied parameters, particularly those used in administrative functions. The recommended approach includes applying the vendor-supplied patch or upgrade to a version that addresses this specific vulnerability. Organizations should also consider implementing web application firewalls to detect and block malicious requests targeting the vulnerable table_width parameter. Network segmentation and access controls should be strengthened to limit exposure, while regular security assessments should be conducted to identify similar vulnerabilities in other applications. Additionally, the principle of least privilege should be enforced by ensuring that administrative scripts operate with minimal necessary permissions and that all user inputs are properly escaped before processing. Security monitoring should be enhanced to detect anomalous behavior patterns that might indicate exploitation attempts.