CVE-2000-1176 in YaBB SE
Summary
by MITRE
Directory traversal vulnerability in YaBB search.pl CGI script allows remote attackers to read arbitrary files via a .. (dot dot) attack in the "catsearch" form field.
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Analysis
by VulDB Data Team • 10/11/2025
The vulnerability identified as CVE-2000-1176 represents a classic directory traversal flaw within the YaBB forum software's search.pl CGI script. This security weakness resides in the improper validation of user input parameters, specifically the "catsearch" form field that processes directory navigation requests. The flaw enables malicious actors to manipulate file system access by injecting directory traversal sequences using the .. (dot dot) notation. When the search.pl script processes these inputs without adequate sanitization, it fails to restrict access to files outside the intended directory structure, creating a pathway for unauthorized file retrieval.
This directory traversal vulnerability operates at the application layer and falls under the Common Weakness Enumeration category CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory. The attack vector involves sending crafted HTTP requests to the vulnerable CGI script where the attacker can specify arbitrary directory paths through the catsearch parameter. The technical implementation of this flaw demonstrates a failure in input validation and path resolution within the YaBB forum's search functionality, allowing attackers to bypass normal file system access controls. The vulnerability is particularly dangerous because it can be exploited remotely without requiring authentication or special privileges, making it a significant threat to web application security.
The operational impact of CVE-2000-1176 extends beyond simple file reading capabilities to encompass potential data exfiltration and system compromise. Attackers can leverage this vulnerability to access sensitive files such as configuration settings, user credentials, database connection details, or even system files that should remain inaccessible to unauthorized users. The implications for organizations using vulnerable YaBB installations include potential exposure of confidential information, system integrity compromise, and possible escalation to more severe attacks. This vulnerability aligns with ATT&CK technique T1083 (File and Directory Discovery) and T1566 (Phishing) as attackers may use the retrieved information to craft more sophisticated social engineering campaigns or to identify additional system vulnerabilities.
Mitigation strategies for this directory traversal vulnerability must address both immediate remediation and long-term security improvements. The primary solution involves implementing proper input validation and sanitization within the search.pl script to reject or escape directory traversal sequences before processing user inputs. Organizations should also apply the latest security patches provided by YaBB developers or migrate to more secure forum solutions that have addressed this class of vulnerability. Network-level protections such as web application firewalls can provide additional defense-in-depth measures by monitoring for suspicious directory traversal patterns in HTTP requests. Regular security assessments and code reviews should be conducted to identify similar vulnerabilities in other CGI scripts or web applications, as directory traversal flaws are common across many web platforms and often stem from the same root cause of inadequate input validation.