CVE-2004-2014 in wget
Summary
by MITRE
Wget 1.9 and 1.9.1 allows local users to overwrite arbitrary files via a symlink attack on the name of the file being downloaded.
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Analysis
by VulDB Data Team • 12/16/2024
The vulnerability identified as CVE-2004-2014 affects Wget versions 1.9 and 1.9.1, representing a classic file system race condition that enables local attackers to manipulate file creation processes through symbolic link manipulation. This flaw resides in the download handling mechanism where Wget creates temporary files during the retrieval process, creating opportunities for privilege escalation and file overwriting attacks. The vulnerability stems from insufficient validation of file paths and lack of proper atomic file creation procedures, allowing malicious actors to substitute intended download targets with symbolic links pointing to sensitive system files.
The technical implementation of this vulnerability involves a time-of-check to time-of-use race condition where Wget first checks if a file exists and then proceeds to create or overwrite it. During this window, a local attacker can create symbolic links with the same names as the files being downloaded, effectively redirecting the download process to overwrite arbitrary files on the system. This type of vulnerability maps directly to CWE-367, which describes Time-of-Check to Time-of-Use race conditions, and falls under the broader category of improper file access control issues. The attack vector requires local system access and relies on the attacker's ability to manipulate the file system environment during the download process.
The operational impact of this vulnerability extends beyond simple file overwriting, as it can potentially allow attackers to modify critical system files, configuration data, or even executable programs that could lead to privilege escalation. When Wget is executed with elevated privileges, such as through sudo or as part of system maintenance processes, the consequences become significantly more severe. Attackers can exploit this to overwrite files in system directories, potentially compromising system integrity and creating persistent backdoors. The vulnerability affects any environment where Wget is used for downloading files, particularly in automated scripts, system administration tasks, or environments where users might execute wget commands with elevated privileges.
Mitigation strategies for CVE-2004-2014 focus primarily on upgrading to patched versions of Wget where the race condition has been addressed through proper atomic file creation methods and enhanced file path validation. System administrators should implement strict file permissions and access controls to limit the potential damage from such attacks. The use of sandboxed environments for downloading operations, combined with regular system audits and monitoring for unauthorized file modifications, provides additional layers of protection. Organizations should also consider implementing automated patch management processes to ensure timely updates of vulnerable software components. This vulnerability demonstrates the critical importance of proper file system operations and race condition prevention in security-sensitive applications, aligning with ATT&CK technique T1059.007 for execution through command and scripting interpreter and T1548.003 for abuse of sudo privileges, both of which can be leveraged in exploiting such file system vulnerabilities.