CVE-2004-0388 in MySQL
Summary
by MITRE
The mysqld_multi script in MySQL allows local users to overwrite arbitrary files via a symlink attack.
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Analysis
by VulDB Data Team • 07/12/2025
The CVE-2004-0388 vulnerability represents a critical local privilege escalation issue within the MySQL database management system's mysqld_multi utility. This flaw specifically affects the script's handling of temporary files during the multi-instance database startup process, creating a window of opportunity for local attackers to manipulate the system's file structure through symbolic link manipulation techniques. The vulnerability resides in the script's insecure temporary file creation practices, which allow malicious users to create symbolic links that point to sensitive system files, thereby enabling them to overwrite critical system components with arbitrary content.
The technical implementation of this vulnerability stems from the mysqld_multi script's failure to properly validate or secure temporary file operations during database instance management. When the script executes database startup procedures, it creates temporary files in predictable locations without adequate security measures to prevent symlink attacks. Attackers can exploit this by creating symbolic links with names that match those expected by the script, effectively redirecting the script's file operations to target arbitrary files on the system. This behavior directly violates the principle of least privilege and demonstrates poor secure coding practices that have been addressed in modern software development standards. The vulnerability aligns with CWE-377, which addresses insecure temporary file creation, and CWE-276, which covers improper file permissions, both of which are fundamental security concerns in system programming.
From an operational impact perspective, this vulnerability enables local users to potentially overwrite critical system files, including configuration files, binary executables, or even system libraries, which could lead to complete system compromise or denial of service conditions. The attack requires local system access but does not necessitate network connectivity or complex exploitation techniques, making it particularly dangerous in environments where local user access is not properly restricted. The vulnerability affects multiple MySQL versions and demonstrates how seemingly innocuous utility scripts can introduce significant security risks when not properly secured against common attack vectors such as symlink manipulation. Organizations running MySQL installations are at risk of unauthorized file modification, data corruption, or privilege escalation attacks that could ultimately lead to complete system takeover.
The recommended mitigations for this vulnerability encompass both immediate and long-term security measures to protect against symlink-based attacks. System administrators should immediately apply the vendor-provided security patches that address the temporary file handling issues in mysqld_multi. Additionally, the script should be configured to run with minimal necessary privileges, and the temporary file directories should be secured with appropriate file permissions to prevent unauthorized symbolic link creation. Implementing proper input validation and using atomic file creation techniques can prevent the symlink attack vectors that enable this vulnerability. Organizations should also consider implementing automated security monitoring to detect suspicious file operations and symbolic link creation activities. The remediation process should align with ATT&CK technique T1059.001 for command and script injection, as the vulnerability essentially allows for arbitrary file modification through script execution paths. Regular security audits of system utilities and scripts should be conducted to identify similar insecure temporary file handling patterns that could introduce comparable risks.