CVE-2005-3293 in Xerver
Summary
by MITRE
Xerver 4.17 allows remote attackers to (1) obtain source code of scripts via a request with a trailing "." (dot) or (2) list directory contents via a trailing null character.
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Analysis
by VulDB Data Team • 06/10/2019
The vulnerability identified as CVE-2005-3293 affects Xerver 4.17, a web server implementation that exhibits critical security flaws in its handling of file system requests. This vulnerability stems from inadequate input validation and path traversal mechanisms within the server's file access routines, creating opportunities for remote attackers to gain unauthorized access to sensitive server resources. The flaw specifically manifests when the server processes requests containing malformed path specifications that exploit weaknesses in how the software interprets directory navigation sequences.
The technical implementation of this vulnerability involves two distinct attack vectors that leverage different aspects of path handling. The first vector allows attackers to retrieve source code of server scripts by appending a trailing dot character to file requests, which causes the server to interpret the request as a directory listing operation rather than a file retrieval. This behavior stems from improper path normalization routines that fail to properly sanitize trailing characters in file paths. The second vector exploits a trailing null character appended to requests, which enables directory enumeration by bypassing normal access controls and file system boundary checks.
From an operational perspective, this vulnerability presents significant risks to server security and data integrity. Remote attackers can leverage these flaws to access sensitive source code files that may contain database connection strings, authentication mechanisms, business logic implementations, and other proprietary code that could be used for further exploitation. The directory listing capability provides attackers with comprehensive knowledge of server file structures, enabling them to identify additional targets for exploitation and plan more sophisticated attacks. This vulnerability directly impacts the confidentiality and integrity aspects of the CIA triad, as it allows unauthorized data access and potential modification of server resources.
The vulnerability aligns with CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) and CWE-35 path traversal vulnerabilities, representing classic examples of insufficient input validation and improper access control mechanisms. Attackers can potentially map this vulnerability to techniques described in the MITRE ATT&CK framework under T1083 (File and Directory Discovery) and T1566 (Phishing with Malicious Attachments) to escalate privileges and conduct more extensive reconnaissance. The lack of proper input sanitization creates a persistent security gap that could be exploited by automated scanning tools to identify vulnerable systems across the internet.
Organizations should implement immediate mitigations including updating to patched versions of Xerver or implementing web application firewalls that can detect and block malformed path requests. Network segmentation and access controls should be strengthened to limit exposure of vulnerable servers. Regular security audits should include verification of path handling routines and proper input validation mechanisms. The vulnerability demonstrates the critical importance of proper path normalization and input sanitization in web server implementations, as these fundamental security measures prevent attackers from exploiting path traversal flaws that have been prevalent in web server software for decades.