CVE-2009-3544 in Xerver
Summary
by MITRE
Xerver HTTP Server 4.32 allows remote attackers to obtain the source code for a web page via an HTTP request with the addition of ::$DATA after the HTML file name.
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Analysis
by VulDB Data Team • 12/14/2024
The vulnerability identified as CVE-2009-3544 affects Xerver HTTP Server version 4.32 and represents a critical information disclosure flaw that enables remote attackers to access sensitive source code content. This vulnerability stems from improper input validation and handling within the web server's request processing mechanism, specifically when processing file paths that contain the special sequence ::$DATA appended to HTML file names. The flaw allows unauthorized access to web application source code, potentially exposing sensitive implementation details, business logic, and configuration information that could be exploited by malicious actors.
The technical implementation of this vulnerability demonstrates a classic path traversal or information disclosure weakness where the server fails to properly sanitize or validate file path requests. When an attacker crafts an HTTP request containing ::$DATA after an HTML filename, the server incorrectly processes this input and returns the source code of the requested file rather than the rendered HTML content. This behavior indicates a lack of proper access controls and input sanitization mechanisms that should prevent arbitrary file access. The vulnerability operates at the application layer and can be classified under CWE-200, which specifically addresses information exposure, while also relating to CWE-22 for path traversal attacks and CWE-502 for unsafe deserialization of file paths.
The operational impact of this vulnerability is significant for organizations running affected Xerver HTTP Server versions, as it provides attackers with direct access to web application source code without requiring authentication or specialized privileges. This exposure can lead to comprehensive reconnaissance of web applications, enabling attackers to identify potential security weaknesses, discover hardcoded credentials, understand application architecture, and potentially identify additional vulnerabilities. The vulnerability can be exploited remotely without any prior access or credentials, making it particularly dangerous in production environments where sensitive source code may contain business logic, database connection strings, or other confidential information. From an attack framework perspective, this vulnerability aligns with ATT&CK technique T1566 for initial access through web application attacks and T1083 for file and directory discovery.
Organizations affected by this vulnerability should implement immediate mitigations including upgrading to a patched version of Xerver HTTP Server that properly validates and sanitizes file path inputs. Network administrators should consider implementing web application firewalls or intrusion prevention systems that can detect and block requests containing the ::$DATA pattern. Additionally, the server configuration should be reviewed to ensure that source code files are not directly accessible through the web root and that proper access controls are implemented. Regular security assessments should include checking for similar vulnerabilities in other web server implementations and ensuring that all file access operations properly validate input parameters. The vulnerability highlights the importance of proper input validation and the principle of least privilege in web server configurations, where unnecessary file access capabilities should be disabled to prevent information disclosure attacks.