CVE-2003-0367 in Mandrake Linux
Summary
by MITRE
znew in the gzip package allows local users to overwrite arbitrary files via a symlink attack on temporary files.
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Analysis
by VulDB Data Team • 06/28/2021
The vulnerability identified as CVE-2003-0367 resides within the gzip package's znew utility, representing a classic symlink attack scenario that enables local users to overwrite arbitrary files on a system. This flaw specifically manifests when the znew utility creates temporary files during its operation, failing to properly validate or secure these temporary file operations. The vulnerability falls under the category of insecure temporary file handling, which is categorized as CWE-377 by the Common Weakness Enumeration framework, and directly relates to the broader class of insecure file handling practices that attackers exploit to gain unauthorized access or modify system resources.
The technical implementation of this vulnerability exploits the predictable naming patterns of temporary files used by znew, combined with the absence of proper file access controls during temporary file creation. When a local user can manipulate the environment in which znew operates, they can create symbolic links that point to sensitive system files or directories. During the execution of znew, when the utility attempts to create its temporary file, it follows the symbolic link and writes data to the target file instead of the intended temporary location. This type of attack aligns with the ATT&CK technique T1059.007 for execution through symbolic links and represents a privilege escalation vector that can be exploited by unprivileged users to modify files they would normally not have write access to.
The operational impact of CVE-2003-0367 extends beyond simple file overwrites, as it can enable attackers to modify critical system files, configuration data, or even executable components that could lead to further compromise of the affected system. The vulnerability is particularly concerning because it operates at the local user level, meaning any user with access to the system can potentially exploit it, making it a significant concern for multi-user environments and systems where users may have varying levels of privileges. This type of flaw can be leveraged to create backdoors, modify system integrity, or interfere with normal system operations, potentially leading to more severe security incidents.
Mitigation strategies for CVE-2003-0367 should focus on implementing proper temporary file handling practices that prevent symlink attacks. The most effective approach involves using secure temporary file creation methods that check for the existence of files before creating them, or implementing proper file permissions and ownership checks during temporary file operations. System administrators should also consider updating to newer versions of gzip that address this vulnerability through improved temporary file handling mechanisms. The remediation aligns with security best practices outlined in the OWASP Top Ten and follows the principle of least privilege by ensuring that temporary file operations do not create security risks for other users or system components. Additionally, regular security audits and monitoring of system file integrity can help detect unauthorized modifications that might result from exploitation of this vulnerability, making it part of a comprehensive defense-in-depth strategy.