Command Injection in LuCI-proto-openvpn

Executive Summary

CVE-2026-58000 is a high-severity command injection vulnerability in the luci-proto-openvpn package of the OpenWrt LuCI web interface. The vulnerability exists in the generateKey ubus method where the cl_meta parameter is directly interpolated into a shell command without proper escaping or quoting.

An authenticated LuCI user with access to the OpenVPN protocol configuration can inject arbitrary shell metacharacters into the cl_meta parameter, allowing execution of arbitrary commands as the root user via the popen function.

This occurs because the rpcd process runs with root privileges and the cl_meta parameter is not properly sanitized, leading to potential full system compromise.

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Impact Analysis

This vulnerability allows an authenticated user with OpenVPN protocol configuration access to execute arbitrary commands as the root user on the affected system.

Exploitation can lead to full system compromise, including unauthorized control over the device, data theft, service disruption, or further attacks within the network.

Because the attack complexity is low and no additional user interaction is required, the risk is considered high.

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Detection Guidance

This vulnerability can be detected by monitoring for unusual or unauthorized usage of the generateKey ubus method in the luci-proto-openvpn package, especially calls that include suspicious shell metacharacters in the cl_meta parameter.

Since exploitation involves injecting shell commands via the cl_meta parameter, you can look for abnormal ubus API calls or RPC requests containing suspicious payloads such as shell metacharacters like $(id), ; reboot #, or other command injection patterns.

Commands to detect potential exploitation attempts might include:

• Checking ubus call logs or rpcd logs for suspicious cl_meta values containing shell metacharacters.
• Using network monitoring tools to capture and inspect RPC or ubus traffic for suspicious payloads targeting the generateKey method.
• Example command to search logs for suspicious cl_meta usage: `grep -E 'cl_meta.*[;$\(\)]' /var/log/rpcd.log` (adjust log path as needed).

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Mitigation Strategies

The immediate mitigation step is to update the luci-proto-openvpn package to a version that includes the fix from commit e4ff45e, which properly escapes the cl_meta parameter to prevent command injection.

If an update is not immediately possible, restrict access to the LuCI OpenVPN protocol configuration interface to trusted users only, as exploitation requires authenticated access.

Additionally, monitor and audit ubus API calls for suspicious activity targeting the generateKey method.

Applying the patch or upgrade will ensure the cl_meta parameter is safely quoted using shellquote, preventing arbitrary command execution.

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Compliance Impact

The vulnerability allows an authenticated user with OpenVPN protocol configuration access to execute arbitrary commands as root, leading to full system compromise.

Such a compromise could result in unauthorized access to sensitive data or disruption of system integrity, which may violate common standards and regulations like GDPR and HIPAA that require protection of data confidentiality, integrity, and availability.

However, the provided information does not explicitly discuss the impact on compliance with these standards.

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