CVE-2004-0996 in Linux
Summary
by MITRE
main.c in cscope 15-4 and 15-5 creates temporary files with predictable filenames, which allows local users to overwrite arbitrary files via a symlink attack.
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Analysis
by VulDB Data Team • 12/03/2024
The vulnerability described in CVE-2004-0996 represents a classic file system security flaw affecting the cscope source code navigation tool version 15-4 and 15-5. This issue stems from the tool's improper handling of temporary file creation during its operation, specifically within the main.c component. The vulnerability enables local attackers to exploit predictable filename patterns to perform symlink-based file overwrite attacks, potentially compromising system integrity and confidentiality.
The technical implementation of this vulnerability occurs when cscope generates temporary files using predictable naming conventions rather than secure randomized names. When the application creates temporary files with known, static filenames, an attacker can establish symbolic links with identical names in the target directory before cscope executes. This race condition scenario allows the attacker to control what files get overwritten or modified, potentially leading to privilege escalation or unauthorized data manipulation. The flaw directly relates to CWE-377, which addresses insecure temporary file creation practices, and specifically manifests as a race condition vulnerability where the timing between symlink creation and file access creates exploitable conditions.
The operational impact of this vulnerability extends beyond simple file overwrites, as it can enable attackers to manipulate critical system files or configuration data that cscope might access during its operation. Local users with minimal privileges can potentially escalate their access level by overwriting system binaries, configuration files, or other sensitive data structures. This vulnerability particularly affects Unix-like systems where cscope is commonly deployed for source code navigation and analysis. The attack vector is straightforward and requires minimal expertise, making it a significant security concern for systems where cscope is regularly used with elevated privileges or in environments with multiple users.
Mitigation strategies for this vulnerability primarily focus on implementing secure temporary file creation practices that prevent predictable filename generation. System administrators should ensure that cscope is updated to versions that address this issue through proper randomization of temporary file names or by using secure file creation functions that prevent symlink attacks. The recommended approach aligns with ATT&CK technique T1059.007 for executing commands through the shell and T1548.001 for privilege escalation. Organizations should also implement proper file system permissions and monitoring to detect unauthorized symlink creation attempts. Additionally, the principle of least privilege should be enforced, limiting the execution of cscope with elevated privileges and ensuring that temporary file directories are properly secured against symlink attacks. Regular security audits and vulnerability assessments should include checks for similar predictable temporary file creation patterns in other applications to prevent similar issues from occurring in the broader system landscape.