CVE-2009-0852 in CelerBB
Summary
by MITRE
showme.php in CelerBB 0.0.2 allows remote attackers to obtain "reserved information" via the user parameter.
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Analysis
by VulDB Data Team • 11/24/2024
The vulnerability identified as CVE-2009-0852 affects CelerBB version 0.0.2, a bulletin board system that was widely used in web applications during that era. This flaw resides in the showme.php script which processes user requests and handles parameter input from web clients. The vulnerability represents a classic information disclosure issue where an attacker can manipulate the user parameter to access sensitive data that should remain restricted to authorized users or system internals. The affected application fails to properly validate or sanitize input parameters before processing them, creating a pathway for unauthorized data retrieval.
The technical implementation of this vulnerability stems from inadequate input validation mechanisms within the showme.php script. When a user parameter is passed to the application, the system does not sufficiently filter or sanitize this input before using it in database queries or file operations. This allows an attacker to craft malicious input that can trigger the application to reveal internal system information, configuration details, or other sensitive data that should not be accessible through normal user operations. The vulnerability operates at the application layer and requires no special privileges to exploit, making it particularly dangerous as it can be leveraged by any remote attacker with knowledge of the application's structure.
From an operational impact perspective, this vulnerability exposes the system to significant risk of information disclosure attacks that can lead to further exploitation. An attacker who successfully exploits this vulnerability can potentially obtain database connection strings, user credentials, system paths, or other sensitive configuration data that could be used to escalate privileges or launch additional attacks. The disclosed information might include database schema details, application logic flows, or internal server configurations that provide attackers with valuable insights for subsequent compromise attempts. This type of vulnerability directly violates the principle of least privilege and can undermine the confidentiality controls of the affected system.
The vulnerability maps to CWE-200, which specifically addresses "Information Exposure," and aligns with several ATT&CK techniques including T1083 (File and Directory Discovery) and T1213 (Data from Information Repositories). Organizations affected by this vulnerability should implement immediate mitigations including input validation and sanitization of all user parameters, proper access controls on sensitive files and database queries, and comprehensive application security testing. The recommended approach involves filtering all input parameters through strict validation routines, implementing proper error handling that does not reveal system internals, and ensuring that sensitive information is not exposed through application responses. Additionally, regular security audits and code reviews should be conducted to identify similar vulnerabilities in legacy applications and prevent similar issues from occurring in future deployments.
This vulnerability demonstrates the critical importance of input validation and proper access control mechanisms in web applications, particularly in legacy systems that may not have been designed with modern security considerations in mind. The ease of exploitation combined with the potential for significant information disclosure makes this a serious concern for organizations running affected versions of CelerBB, requiring immediate remediation efforts to protect against potential compromise.