CVE-2011-3695 in 111WebCalendar
Summary
by MITRE
111WebCalendar 1.2.3 allows remote attackers to obtain sensitive information via a direct request to a .php file, which reveals the installation path in an error message, as demonstrated by footer.php and certain other files.
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Analysis
by VulDB Data Team • 02/10/2019
The vulnerability identified as CVE-2011-3695 affects 111WebCalendar version 1.2.3 and represents a classic information disclosure flaw that exposes sensitive system details to remote attackers. This type of vulnerability falls under the category of improper error handling and sensitive data exposure, which are commonly classified under CWE-209 and CWE-200 in the Common Weakness Enumeration framework. The flaw manifests when attackers can directly access php files within the application's directory structure, specifically targeting files like footer.php and other related components. When these files are accessed without proper authentication or input validation, they generate error messages that inadvertently reveal the absolute installation path of the web application on the server filesystem.
The technical exploitation of this vulnerability occurs through simple HTTP requests directed at specific php files within the application's directory structure. Attackers can craft malicious requests that bypass normal application logic and trigger error conditions within the php files. These error conditions contain verbose debugging information that includes the full file system path where the application is installed, typically formatted as something like /var/www/html/calendar/footer.php or similar server-specific paths. The vulnerability is particularly dangerous because it provides attackers with crucial information needed for subsequent exploitation attempts, including the exact location of the web application within the server's file system hierarchy. This information can be used to plan more sophisticated attacks, such as local file inclusion vulnerabilities or to understand the server's directory structure for further reconnaissance.
The operational impact of this vulnerability extends beyond simple information disclosure, as it significantly weakens the overall security posture of the affected system. The exposure of installation paths can enable attackers to craft more targeted attacks against the web application and potentially the underlying server infrastructure. According to the MITRE ATT&CK framework, this vulnerability maps to the T1083 technique for discovering system information, which is often used in the initial reconnaissance phase of cyber attacks. The disclosed information can be leveraged to bypass security controls, understand the application's architecture, and potentially identify other vulnerabilities within the same system. Additionally, the vulnerability can be combined with other attack vectors to create more complex exploitation scenarios, making it particularly dangerous in environments where multiple applications share similar directory structures or where the disclosed path information can be used to map the entire server environment.
The recommended mitigation strategies for CVE-2011-3695 involve implementing proper error handling mechanisms and removing or disabling direct access to sensitive php files within the application. System administrators should configure the web server to prevent direct access to php files that might generate error messages containing sensitive information. This can be achieved through proper .htaccess configurations, web server access controls, or application-level input validation that prevents unauthorized access to internal files. The implementation of custom error pages that do not reveal system information is crucial, as is ensuring that error messages displayed to end users do not contain any server path information. Additionally, regular security audits should be conducted to identify and remediate similar vulnerabilities in other applications, and the application should be updated to a newer version that addresses this specific flaw. Organizations should also implement logging mechanisms to detect and alert on unauthorized access attempts to sensitive files, as this information disclosure can serve as an early indicator of potential security breaches. The vulnerability highlights the importance of secure coding practices and proper error handling in web applications, as even seemingly minor flaws can provide attackers with critical information needed for more sophisticated attacks.