CVE-2002-0307 in Avengers News System
Summary
by MITRE
Directory traversal vulnerability in ans.pl in Avenger s News System (ANS) 2.11 and earlier allows remote attackers to determine the existence of arbitrary files or execute any Perl program on the system via a .. (dot dot) in the p parameter, which reads the target file and attempts to execute the line using Perl s eval function.
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Analysis
by VulDB Data Team • 06/18/2024
The CVE-2002-0307 vulnerability represents a critical directory traversal flaw in Avenger s News System version 2.11 and earlier, demonstrating a fundamental security weakness in input validation and file access controls. This vulnerability specifically affects the ans.pl script which processes user input through the p parameter, creating an exploitable condition where remote attackers can manipulate file paths to access arbitrary files on the system. The flaw arises from insufficient sanitization of user-supplied data, allowing malicious actors to append directory traversal sequences such as .. to navigate outside the intended directory boundaries. The vulnerability operates at the application level and directly impacts the system s file access mechanisms, potentially enabling both information disclosure and arbitrary code execution.
The technical exploitation mechanism leverages the Perl programming language s eval function, which processes and executes code dynamically at runtime. When the ans.pl script receives a malicious p parameter containing directory traversal sequences, it reads the target file and subsequently attempts to execute the contents using Perl s eval functionality. This creates a dangerous execution path where attacker-controlled data can be interpreted and executed as Perl code, effectively providing remote code execution capabilities. The vulnerability is classified under CWE-22 as "Improper Limitation of a Pathname to a Restricted Directory" and aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: Perl," demonstrating how improper input handling can lead to arbitrary code execution in interpreted languages.
The operational impact of this vulnerability extends beyond simple file access, as it provides attackers with the ability to determine the existence of arbitrary files on the system and potentially execute any Perl program available. This capability enables attackers to perform reconnaissance activities, access sensitive configuration files, and ultimately gain control over the affected system. The vulnerability affects systems running the vulnerable version of Avenger s News System, which could include web servers hosting news or content management applications. Attackers can exploit this flaw remotely without requiring authentication, making it particularly dangerous in publicly accessible environments where the application is deployed. The implications include potential data breaches, system compromise, and unauthorized access to system resources.
Mitigation strategies for CVE-2002-0307 should focus on implementing proper input validation and sanitization mechanisms to prevent directory traversal attacks. Organizations should immediately upgrade to a patched version of Avenger s News System or implement proper parameter validation that filters out directory traversal sequences such as .. or %2e%2e. The solution should involve implementing a whitelist approach for acceptable file paths and ensuring that all user input is properly sanitized before being processed by the application. Additionally, system administrators should consider implementing web application firewalls and input validation rules that specifically target directory traversal patterns. The remediation process should also include disabling unnecessary file access capabilities and ensuring that the application runs with minimal required privileges to limit potential damage from successful exploitation attempts.