CVE-2003-0261 in Fuzz
Summary
by MITRE
fuzz 0.6 and earlier creates temporary files insecurely, which could allow local users to gain root privileges.
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Analysis
by VulDB Data Team • 04/22/2019
The vulnerability identified as CVE-2003-0261 affects fuzz version 0.6 and earlier, presenting a critical security flaw in how the application handles temporary file creation. This issue stems from insecure temporary file handling practices that can be exploited by local attackers to escalate their privileges to root level access. The flaw specifically manifests when the fuzz application creates temporary files without proper security measures, leaving them susceptible to manipulation by malicious users. The vulnerability represents a classic privilege escalation vector that leverages weak file system permissions and insecure temporary file creation mechanisms. Security researchers have classified this as a local privilege escalation vulnerability due to its reliance on local system access and the potential for elevated privileges through exploitation of the temporary file creation process.
The technical implementation of this vulnerability involves the fuzz application's failure to properly secure temporary file creation operations. When fuzz generates temporary files, it typically creates them in predictable locations with insufficient permission controls, allowing local users to either replace the temporary files with malicious content or predict the file names and manipulate them before execution. This insecure practice often involves creating files in world-writable directories or using predictable naming conventions that enable attackers to intercept or substitute the temporary files. The vulnerability can be exploited through race conditions where the attacker creates symbolic links or hard links to target files, or by directly overwriting temporary files with malicious content. This flaw directly relates to CWE-377, which addresses insecure temporary file creation practices, and represents a common pattern in privilege escalation vulnerabilities where inadequate security controls during file operations enable attackers to gain elevated privileges.
The operational impact of this vulnerability extends beyond simple privilege escalation to potentially compromise entire system security. Local users who exploit this vulnerability can gain root access, enabling them to modify system files, install malicious software, create new user accounts, or access sensitive data that would otherwise be protected. The exploitation requires local system access but does not require network connectivity, making it particularly dangerous in environments where local access is possible. Attackers can leverage this vulnerability to establish persistent access, escalate privileges silently, and potentially use the root access to compromise other system components or exfiltrate data. The impact is amplified in multi-user environments where local access might be more readily available, and the vulnerability can be exploited to maintain persistence even after system reboots if proper mitigation is not implemented. This vulnerability aligns with ATT&CK technique T1068, which covers local privilege escalation through insecure file handling, and demonstrates how seemingly minor implementation flaws can result in critical security breaches.
Mitigation strategies for CVE-2003-0261 involve immediate patching of the fuzz application to version 0.7 or later, which addresses the insecure temporary file creation issue. System administrators should implement proper temporary file handling practices, including using secure temporary file creation functions that provide appropriate permissions and unpredictable file names. The recommended approach includes setting restrictive permissions on temporary directories, using umask settings to ensure proper file permissions, and avoiding predictable naming schemes for temporary files. Organizations should also implement monitoring for suspicious temporary file creation patterns and consider privilege separation techniques to limit the impact of potential exploitation. Additionally, the use of secure temporary file creation APIs and libraries that automatically handle proper file permissions and atomic operations can prevent similar vulnerabilities from occurring in other applications. Regular security audits of system applications should include review of temporary file handling practices, and system hardening measures should enforce strict controls over temporary file operations to prevent exploitation of similar vulnerabilities. The fix typically involves implementing proper temporary file creation mechanisms that ensure atomic operations and appropriate file permissions, thereby eliminating the window of opportunity for attackers to manipulate temporary files during the application execution process.