CVE-2025-3908

The configuration initialization tool in OpenVPN 3 Linux v20 through v24 on Linux allows a local attacker to use symlinks pointing at an arbitrary directory which will change the ownership and permissions of that destination directory.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Potential Mitigations

• Follow the principle of least privilege when assigning access rights to entities in a software system.
• Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/132.html
• https://cwe.mitre.org/data/definitions/17.html
• https://cwe.mitre.org/data/definitions/35.html
• https://cwe.mitre.org/data/definitions/76.html

References

• https://community.openvpn.net/Security%20Announcements/CVE-2025-3908
• http://www.openwall.com/lists/oss-security/2025/05/20/2