CVE-2009-2648 in Guestbook
Summary
by MITRE
FlashDen Guestbook allows remote attackers to obtain configuration information via a direct request to amfphp/phpinfo.php, which calls the phpinfo function.
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Analysis
by VulDB Data Team • 08/14/2017
The vulnerability described in CVE-2009-2648 represents a critical information disclosure flaw within the FlashDen Guestbook web application. This issue arises from the application's improper handling of direct requests to specific endpoints, specifically the amfphp/phpinfo.php file. The vulnerability allows remote attackers to bypass normal access controls and directly retrieve sensitive system configuration information through a simple HTTP request. The flaw stems from the application's failure to implement proper authentication and authorization mechanisms for administrative or diagnostic endpoints, creating an attack surface that exposes internal server details to unauthorized parties.
The technical implementation of this vulnerability involves the direct invocation of the phpinfo function within the amfphp/phpinfo.php script. This PHP function is designed to display extensive information about the server's PHP configuration, including loaded modules, system environment variables, configuration settings, and potentially sensitive details about the underlying infrastructure. When accessed directly without proper authentication, this endpoint becomes a vector for attackers to gather comprehensive information about the target system's configuration, which can significantly aid in subsequent exploitation attempts. The vulnerability operates at the application layer and demonstrates poor input validation and access control implementation, making it particularly dangerous as it requires minimal effort to exploit.
The operational impact of this vulnerability extends beyond simple information disclosure, as the gathered configuration information can enable more sophisticated attacks. Attackers can use the exposed phpinfo output to identify installed PHP extensions, server versions, and potential security misconfigurations that may lead to further exploitation. This information disclosure can facilitate attacks such as privilege escalation, remote code execution, or the identification of other vulnerable components within the system. The vulnerability aligns with CWE-200, which categorizes information disclosure flaws, and represents a classic example of how insecure direct object references can compromise system security. The attack vector is particularly concerning as it requires no special privileges or complex exploitation techniques, making it accessible to attackers with basic web reconnaissance capabilities.
Organizations affected by this vulnerability should implement immediate mitigations to prevent unauthorized access to diagnostic endpoints. The primary remediation involves restricting access to the amfphp/phpinfo.php file through proper authentication mechanisms, IP address filtering, or by removing the file entirely if it is not essential for legitimate operations. Additionally, implementing proper input validation and access control checks for all application endpoints can prevent similar issues from occurring in other parts of the system. Security monitoring should be enhanced to detect and alert on suspicious requests to diagnostic endpoints, while regular security assessments should be conducted to identify other potential insecure direct object references. The vulnerability demonstrates the importance of following secure coding practices and implementing defense-in-depth strategies to protect against information disclosure attacks that can compromise entire systems.