CVE-2004-1107 in Portage
Summary
by MITRE
dispatch-conf in Portage 2.0.51-r2 and earlier allows local users to overwrite arbitrary files via a symlink attack on temporary files.
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Analysis
by VulDB Data Team • 06/20/2019
The vulnerability identified as CVE-2004-1107 affects the dispatch-conf utility within Portage package management system version 2.0.51-r2 and earlier. This flaw represents a classic symlink attack scenario that exploits insecure temporary file handling practices. The dispatch-conf utility is designed to help users manage configuration file conflicts during package updates by presenting them with options to keep, replace, or merge configuration files from different package versions. However, the vulnerability arises from the utility's failure to properly validate temporary file creation processes, creating opportunities for local attackers to manipulate the system's file operations through symbolic link manipulation.
The technical implementation of this vulnerability stems from the insecure creation of temporary files without proper security checks. When dispatch-conf executes, it creates temporary files in predictable locations without verifying that these files are not symbolic links or do not point to locations outside the intended scope. This insecure practice directly violates the principle of secure temporary file creation as outlined in CWE-377, which specifically addresses the creation of temporary files with insecure permissions or predictable names. Attackers can exploit this by creating symbolic links in the temporary file paths that point to sensitive system files, allowing them to overwrite arbitrary files with malicious content when the utility processes these temporary files.
The operational impact of this vulnerability is significant for local users who have access to the system, as it provides a means to escalate privileges or compromise system integrity. Since the vulnerability requires local access, it primarily affects scenarios where attackers already have a foothold on the system, but the potential for privilege escalation or data corruption remains high. The attack vector is particularly concerning because it leverages the legitimate system utility used for configuration management, making it less likely to raise immediate security alerts. This vulnerability can be exploited to overwrite critical system files, configuration files, or even user data, potentially leading to system instability, unauthorized access, or complete system compromise.
Mitigation strategies for this vulnerability should focus on immediate patching of affected Portage versions to 2.0.51-r3 or later, which contain the necessary security fixes. System administrators should also implement additional security measures such as monitoring for unauthorized symlink creation in temporary directories and ensuring proper file permissions on system configuration files. The fix typically involves implementing proper temporary file handling techniques that check for existing symbolic links before creating temporary files, as recommended by the ATT&CK framework for preventing privilege escalation through insecure file operations. Organizations should also consider implementing automated security scanning to identify similar insecure temporary file creation patterns in other system utilities and applications. Additionally, regular security audits of package management systems and configuration utilities should be conducted to prevent similar vulnerabilities from being introduced in future versions. The vulnerability highlights the importance of proper secure coding practices in system utilities, particularly those that handle file operations and user configuration management, as these components often have elevated privileges and are frequently targeted by attackers seeking system compromise.