OpenVPN 2.1 until v2.4.12 and v2.5.6 may enable authentication bypass in external authentication plug-ins when more than one of them makes use of deferred authentication replies, which allows an external user to be granted access with only partially correct credentials.
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Openvpn | Openvpn | 2.1.0 (including) | 2.4.12 (excluding) |
| Openvpn | Openvpn | 2.5.0 (including) | 2.5.6 (excluding) |
| Openvpn | Ubuntu | bionic | * |
| Openvpn | Ubuntu | devel | * |
| Openvpn | Ubuntu | esm-infra/xenial | * |
| Openvpn | Ubuntu | focal | * |
| Openvpn | Ubuntu | impish | * |
| Openvpn | Ubuntu | jammy | * |
| Openvpn | Ubuntu | kinetic | * |
| Openvpn | Ubuntu | lunar | * |
| Openvpn | Ubuntu | mantic | * |
| Openvpn | Ubuntu | noble | * |
| Openvpn | Ubuntu | trusty | * |
| Openvpn | Ubuntu | trusty/esm | * |
| Openvpn | Ubuntu | upstream | * |
| Openvpn | Ubuntu | xenial | * |