Improper validation of source IP addresses in OpenVPN version 2.6.0 through 2.6.15 and 2.7_alpha1 through 2.7_rc1 allows an attacker to open a session from a different IP address which did not initiate the connection resulting in a denial of service for the originating client
Weakness
The product establishes a communication channel to handle an incoming request that has been initiated by an actor, but it does not properly verify that the request is coming from the expected origin.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Openvpn | Openvpn | 2.6.0 (including) | 2.6.16 (excluding) |
| Openvpn | Openvpn | 2.7-alpha1 (including) | 2.7-alpha1 (including) |
| Openvpn | Openvpn | 2.7-alpha2 (including) | 2.7-alpha2 (including) |
| Openvpn | Openvpn | 2.7-alpha3 (including) | 2.7-alpha3 (including) |
| Openvpn | Openvpn | 2.7-beta1 (including) | 2.7-beta1 (including) |
| Openvpn | Openvpn | 2.7-beta2 (including) | 2.7-beta2 (including) |
| Openvpn | Openvpn | 2.7-beta3 (including) | 2.7-beta3 (including) |
| Openvpn | Openvpn | 2.7-rc1 (including) | 2.7-rc1 (including) |
| Openvpn | Ubuntu | devel | * |
| Openvpn | Ubuntu | noble | * |
| Openvpn | Ubuntu | plucky | * |
| Openvpn | Ubuntu | questing | * |
| Openvpn | Ubuntu | upstream | * |
Potential Mitigations
- Use a mechanism that can validate the identity of the source, such as a certificate, and validate the integrity of data to ensure that it cannot be modified in transit using an Adversary-in-the-Middle (AITM) attack.
- When designing functionality of actions in the URL scheme, consider whether the action should be accessible to all mobile applications, or if an allowlist of applications to interface with is appropriate.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/500.html
- https://cwe.mitre.org/data/definitions/594.html
- https://cwe.mitre.org/data/definitions/595.html
- https://cwe.mitre.org/data/definitions/596.html