CVE-2000-1118 in Web Server
Summary
by MITRE
24Link 1.06 web server allows remote attackers to bypass access restrictions by prepending strings such as "/+/" or "/." to the HTTP GET request.
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Analysis
by VulDB Data Team • 04/07/2019
The vulnerability described in CVE-2000-1118 affects the 24Link 1.06 web server implementation and represents a classic path traversal flaw that enables unauthorized access to restricted resources. This issue stems from the server's inadequate input validation mechanisms when processing HTTP GET requests, allowing malicious actors to manipulate file paths through specific string prepending techniques. The vulnerability operates by exploiting the web server's failure to properly sanitize or normalize URI components before processing file access requests, creating a direct pathway for attackers to bypass intended access controls and potentially gain unauthorized access to sensitive system files or directories.
The technical exploitation mechanism relies on the web server's improper handling of special path sequences such as "/+/" or "/." which are prepended to HTTP GET requests. These sequences are designed to manipulate the server's internal file path resolution algorithm, effectively allowing attackers to navigate beyond the intended document root directory. The flaw demonstrates a lack of proper path normalization and canonicalization within the web server's request processing pipeline, where the server fails to properly resolve and validate the absolute path of requested resources. This vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The implementation error occurs at the application layer where the web server processes HTTP requests without adequate security controls to prevent malicious path manipulation.
The operational impact of this vulnerability extends beyond simple unauthorized file access, potentially enabling attackers to execute arbitrary code, read sensitive configuration files, access database contents, or compromise the entire web server infrastructure. When exploited successfully, this vulnerability can provide attackers with complete access to the server's file system, allowing them to retrieve system credentials, application source code, or other confidential information. The attack vector is particularly dangerous because it requires minimal technical expertise to execute and can be automated through standard web scanning tools. This vulnerability also aligns with ATT&CK technique T1083, which describes the discovery of system information through path traversal attacks, and represents a critical weakness in the web server's security posture that could lead to full system compromise.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and path normalization mechanisms within the web server's request processing pipeline. Organizations should ensure that all HTTP GET requests undergo thorough canonicalization to prevent path manipulation attacks, with specific attention to handling special sequences such as "/+/", "/./", and "../" patterns. The recommended approach includes implementing strict path validation that rejects or normalizes any request containing potentially malicious path sequences before they are processed by the file system. Additionally, the web server should be configured with proper access controls that limit file system access to only the intended document root directory, implementing chroot jails or similar isolation techniques to contain potential exploitation attempts. Regular security updates and patches should be applied to eliminate known vulnerabilities, while network segmentation and monitoring should be implemented to detect and prevent exploitation attempts. The vulnerability also highlights the importance of following secure coding practices and conducting regular security assessments to identify and remediate similar path traversal flaws in web applications and server implementations.