OpenVPN before 2.0.1, when running with "verb 0" and without TLS authentication, does not properly flush the OpenSSL error queue when a client fails certificate authentication to the server and causes the error to be processed by the wrong client, which allows remote attackers to cause a denial of service (client disconnection) via a large number of failed authentication attempts.
CVSS Details
- CVSS 3.1 Base Score: 5.3
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade openvpn | Jul 30, 2024 | Aug 24, 2005 |
| Freebsd | — | Upgrade openvpn | Dec 10, 2025 | Aug 19, 2005 |
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