CVE-2004-0689 in KDE
Summary
by MITRE
KDE before 3.3.0 does not properly handle when certain symbolic links point to "stale" locations, which could allow local users to create or truncate arbitrary files.
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Analysis
by VulDB Data Team • 06/29/2019
The vulnerability described in CVE-2004-0689 represents a significant file system permission issue within the KDE desktop environment prior to version 3.3.0. This flaw stems from inadequate handling of symbolic links that reference stale or non-existent locations within the file system hierarchy. The vulnerability specifically affects the way KDE processes symbolic links during file operations, creating a potential privilege escalation vector for local attackers who can manipulate these symbolic link structures.
The technical implementation of this vulnerability lies in KDE's file handling mechanisms where symbolic links are not properly validated before being processed. When a symbolic link points to a location that has been removed or moved, the system fails to properly detect this stale condition and instead proceeds with file operations that can result in unintended file creation or truncation. This behavior occurs because KDE does not implement proper checks to verify the existence and accessibility of the target location before attempting file system operations on symbolic links. The flaw essentially allows an attacker to exploit the symbolic link resolution process to manipulate the file system in ways that should be restricted by normal access controls.
From an operational perspective, this vulnerability poses a serious risk to local system security as it enables attackers with limited privileges to potentially manipulate critical system files or create malicious files in locations where they would normally not have write permissions. The impact extends beyond simple file creation to include the ability to truncate existing files, potentially causing data loss or service disruption. Attackers could leverage this weakness to overwrite configuration files, system binaries, or other critical components, leading to system instability or further compromise. The vulnerability is particularly concerning because it operates at the file system level and can be exploited without requiring network access or complex attack vectors.
The vulnerability maps to CWE-367, which specifically addresses Time-of-Check to Time-of-Use (TOCTOU) flaws in file system operations, and aligns with ATT&CK technique T1068, which covers privilege escalation through local system exploitation. Organizations using affected KDE versions should immediately implement the official patches released by the KDE project to address this issue. Additionally, system administrators should review and tighten file system permissions, particularly for directories that may be subject to symbolic link manipulation. Regular security audits of file system structures and symbolic link usage should be conducted to identify and remediate similar vulnerabilities. The patch for this vulnerability specifically addresses the symbolic link handling logic within KDE's file management components, ensuring that stale symbolic links are properly detected and handled without allowing unauthorized file system modifications.