CVE-2019-12573

A vulnerability in the London Trust Media Private Internet Access (PIA) VPN Client v82 for Linux and macOS could allow an authenticated, local attacker to overwrite arbitrary files. The openvpn_launcher binary is setuid root. This binary supports the –log option, which accepts a path as an argument. This parameter is not sanitized, which allows a local unprivileged user to overwrite arbitrary files owned by any user on the system, including root. This creates a denial of service condition and possible data loss if leveraged by a malicious local user.

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://github.com/mirchr/security-research/blob/master/vulnerabilities/PIA/CVE-2019-12573.txt