CVE-2006-1391 in Baby ASP Web Server
Summary
by MITRE
The (a) Quick n Easy Web Server before 3.1.1 and (b) Baby ASP Web Server 2.7.2 allows remote attackers to obtain the source code of ASP files via (1) . (dot) and (2) space characters in the extension of a URL.
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Analysis
by VulDB Data Team • 09/05/2017
The vulnerability identified as CVE-2006-1391 represents a critical directory traversal and information disclosure flaw affecting two distinct web server implementations: Quick n Easy Web Server versions prior to 3.1.1 and Baby ASP Web Server version 2.7.2. This vulnerability stems from inadequate input validation and path handling mechanisms within these web servers, specifically when processing Uniform Resource Locator requests containing specially crafted file extensions. The flaw exploits the servers' inability to properly sanitize or reject malicious URL patterns that include dot and space characters in file extensions, creating a pathway for remote attackers to access sensitive server-side source code files.
The technical implementation of this vulnerability leverages the servers' file resolution mechanisms to bypass normal access controls and directory restrictions. When a request is made with a URL containing a dot or space character in what appears to be a file extension, the web server's internal path resolution logic fails to properly validate the input, allowing the attacker to traverse the file system and retrieve the source code of ASP files that should remain protected. This behavior aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as directory traversal attacks. The vulnerability specifically targets the web server's handling of file extensions and path resolution, creating a condition where legitimate security boundaries are circumvented through manipulation of URL syntax.
The operational impact of this vulnerability is severe and far-reaching for organizations utilizing these affected web server implementations. Remote attackers can obtain complete source code of ASP applications, which often contains sensitive information including database connection strings, authentication credentials, business logic, and application architecture details. This exposure creates a significant risk for data breaches, application compromise, and subsequent attacks that could leverage the stolen source code for further exploitation. The vulnerability affects not just the immediate disclosure of source code but also potentially exposes underlying system configurations and implementation details that could aid in more sophisticated attacks. According to ATT&CK framework, this vulnerability maps to T1566.001 (Phishing with Malicious Attachments) and T1083 (File and Directory Discovery) as attackers can use the disclosed information to craft more targeted attacks or identify additional system vulnerabilities.
Organizations affected by this vulnerability should immediately implement multiple layers of mitigation strategies to protect their systems. The primary remediation involves upgrading to patched versions of both web server implementations, specifically Quick n Easy Web Server version 3.1.1 or later and Baby ASP Web Server version 2.7.3 or later. Additionally, network-level mitigations should include implementing proper URL filtering and input validation at perimeter defenses, configuring web application firewalls to block suspicious URL patterns containing dots and spaces in file extensions, and establishing robust access controls to limit exposure of sensitive file types. System administrators should also conduct thorough security audits to identify and remediate any additional vulnerable web applications within their infrastructure, as similar vulnerabilities may exist in other web server implementations. The vulnerability demonstrates the critical importance of input validation and proper path handling in web server security, emphasizing that even seemingly benign URL characters can create significant security risks when not properly sanitized.