CVE-2001-1530 in Webmin
Summary
by MITRE
run.cgi in Webmin 0.80 and 0.88 creates temporary files with world-writable permissions, which allows local users to execute arbitrary commands.
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Analysis
by VulDB Data Team • 01/12/2025
The vulnerability described in CVE-2001-1530 affects Webmin versions 0.80 and 0.88 through the run.cgi script that handles temporary file creation during system operations. This flaw represents a critical security issue that stems from improper permission handling in temporary file management. The vulnerability occurs when the run.cgi script creates temporary files without adequately restricting write permissions, allowing local attackers to manipulate these files and potentially execute arbitrary code on the system. This type of vulnerability falls under the category of insecure temporary file creation, which is classified as CWE-377, and specifically relates to CWE-378, which addresses the creation of temporary files with insecure permissions.
The technical implementation of this vulnerability exploits the principle of least privilege by creating temporary files with world-writable permissions, meaning any local user can modify these files. When Webmin executes commands through run.cgi, it often relies on temporary files to store intermediate data or configuration information. Attackers can exploit this by creating symbolic links or replacing these temporary files with malicious content, thereby gaining the ability to execute arbitrary commands with the privileges of the Webmin process. The operational impact is severe as local users who might not have direct access to system commands can leverage this vulnerability to escalate their privileges and potentially compromise the entire system. The vulnerability directly maps to attack techniques in the MITRE ATT&CK framework under T1059 for command and scripting interpreter and T1068 for exploit for privilege escalation.
The security implications extend beyond simple command execution as this vulnerability can be leveraged to establish persistent access or escalate privileges to root level if Webmin runs with elevated permissions. The temporary file creation process typically involves creating files in system directories such as /tmp or /var/tmp, which are commonly used for temporary storage. When these files are created with world-writable permissions, they become prime targets for privilege escalation attacks. The vulnerability demonstrates a fundamental flaw in the software's security design where the principle of least privilege is violated through improper file permission management. System administrators who rely on Webmin for system administration tasks face significant risk if this vulnerability is not addressed, as local users with minimal privileges can exploit it to gain unauthorized access to system resources. The fix for this vulnerability requires ensuring that temporary files are created with restrictive permissions and are properly secured to prevent unauthorized modification or replacement by malicious actors.