CVE-2005-4700 in TellMe
Summary
by MITRE
TellMe 1.2 and earlier, when the Server (o_Server) and HEAD (o_Head) options are enabled, allows remote attackers to obtain sensitive information via an invalid q_Host parameter, which reveals the full pathname of the application in an fsockopen error message.
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Analysis
by VulDB Data Team • 07/16/2018
The vulnerability described in CVE-2005-4700 affects TellMe versions 1.2 and earlier, specifically when the Server and HEAD options are enabled within the application configuration. This flaw represents a classic information disclosure vulnerability that exposes sensitive system details to remote attackers through improper error handling mechanisms. The vulnerability manifests when an invalid q_Host parameter is submitted to the application, causing it to generate an fsockopen error message that inadvertently reveals the full pathname of the application installation directory.
The technical execution of this vulnerability relies on the application's failure to properly sanitize or validate user input parameters before processing them through network operations. When the q_Host parameter contains invalid data, the application attempts to establish a socket connection using the fsockopen function, which generates an error message containing the absolute file path where the application is installed. This occurs because the application does not implement proper error handling or input validation, allowing the underlying system error information to leak through to the client response. The vulnerability is particularly concerning as it exposes the application's physical directory structure, which can provide attackers with crucial information for subsequent exploitation attempts.
From an operational impact perspective, this vulnerability creates significant security risks for systems running affected versions of TellMe. The disclosed pathname information can serve as a foundation for further attacks, including directory traversal attempts, file inclusion vulnerabilities, or other exploitation techniques that rely on knowledge of the application's file structure. Security researchers have classified this as a CWE-200 vulnerability, which specifically addresses improper error handling that leads to information disclosure, and it aligns with ATT&CK technique T1212 for exploitation of information disclosure vulnerabilities. The exposure of system paths can enable attackers to map the application's directory structure, potentially identifying sensitive files, configuration data, or other system resources that could be targeted in additional attacks.
The mitigation strategy for this vulnerability involves several key approaches that address both the immediate flaw and broader security practices. Organizations should immediately upgrade to a patched version of TellMe that properly handles invalid q_Host parameters and prevents error message leakage. Additionally, implementing proper input validation and error handling mechanisms within the application code is essential to prevent similar issues from occurring. This includes sanitizing all user inputs before processing, implementing generic error messages that do not reveal system information, and ensuring that network operations like fsockopen are properly wrapped with exception handling that prevents internal path information from being exposed. Security teams should also consider implementing network-level protections such as web application firewalls that can detect and block malformed requests attempting to exploit this vulnerability, while maintaining regular security assessments to identify other potential information disclosure issues within the application environment.