CVE-2003-1501 in Gast Arbeiter
Summary
by MITRE
Directory traversal vulnerability in the file upload CGI of Gast Arbeiter 1.3 allows remote attackers to write arbitrary files via a .. (dot dot) in the req_file parameter.
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Analysis
by VulDB Data Team • 07/05/2017
The vulnerability described in CVE-2003-1501 represents a critical directory traversal flaw within the file upload functionality of Gast Arbeiter version 1.3, a web-based guestbook application. This vulnerability specifically affects the CGI component responsible for handling file uploads and operates through the req_file parameter which controls the destination path for uploaded files. The flaw enables remote attackers to manipulate the file system by exploiting insufficient input validation mechanisms that fail to properly sanitize user-supplied paths containing directory traversal sequences.
The technical implementation of this vulnerability stems from the application's failure to properly validate and sanitize the req_file parameter before using it to determine the file system path for uploads. When attackers submit malicious input containing .. (dot dot) sequences, the application processes these traversal characters without adequate restrictions, allowing them to navigate outside the intended upload directory. This weakness directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The vulnerability operates by exploiting the fundamental trust placed in user input without proper sanitization, enabling attackers to specify arbitrary file paths that can overwrite system files or create malicious files in unintended locations.
From an operational perspective, this vulnerability poses significant risks to web server security and system integrity. Remote attackers can leverage this flaw to upload malicious files such as web shells, backdoors, or other harmful code that could compromise the entire web server infrastructure. The impact extends beyond simple file manipulation as it can enable attackers to escalate privileges, gain persistent access, or even execute arbitrary code on the target system. The vulnerability affects any system running Gast Arbeiter 1.3 where the file upload functionality is accessible to unauthenticated users, making it particularly dangerous in publicly exposed web applications. Attackers could potentially overwrite critical system files, inject malicious code into existing applications, or establish persistent command and control channels through the uploaded files.
Security professionals should consider this vulnerability in relation to the broader ATT&CK framework, particularly under the T1059.007 technique for Command and Scripting Interpreter and T1566.001 for Pre-Attack - Phishing. The directory traversal capability provides attackers with a pathway to establish persistence and execute commands through uploaded malicious files. Mitigation strategies must include immediate patching of the Gast Arbeiter application to version 1.4 or later, which addresses this specific vulnerability. Additionally, administrators should implement proper input validation and sanitization for all user-supplied parameters, particularly those used in file system operations. The recommended approach involves implementing strict path validation that rejects any input containing directory traversal sequences, enforcing proper access controls on upload directories, and implementing upload restrictions such as file type validation and size limits. Network segmentation and monitoring should also be implemented to detect and prevent exploitation attempts, while regular security assessments should verify that similar vulnerabilities do not exist in other components of the web application stack.