Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, when Envoy is configured in TCP proxy mode to handle CONNECT requests, it accepts client data before issuing a 2xx response and forwards that data to the upstream TCP connection. If a forwarding proxy upstream from Envoy then responds with a non-2xx status, this can cause a de-synchronized CONNECT tunnel state. By default Envoy continues to allow early CONNECT data to avoid disrupting existing deployments. The envoy.reloadable_features.reject_early_connect_data runtime flag can be set to reject CONNECT requests that send data before a 2xx response when intermediaries upstream from Envoy may reject establishment of a CONNECT tunnel.
Weakness
The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Envoy | Envoyproxy | * | 1.33.13 (excluding) |
| Envoy | Envoyproxy | 1.34.0 (including) | 1.34.11 (excluding) |
| Envoy | Envoyproxy | 1.35.0 (including) | 1.35.7 (excluding) |
| Envoy | Envoyproxy | 1.36.0 (including) | 1.36.3 (excluding) |
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/1.html
- https://cwe.mitre.org/data/definitions/107.html
- https://cwe.mitre.org/data/definitions/127.html
- https://cwe.mitre.org/data/definitions/17.html
- https://cwe.mitre.org/data/definitions/20.html
- https://cwe.mitre.org/data/definitions/22.html
- https://cwe.mitre.org/data/definitions/237.html
- https://cwe.mitre.org/data/definitions/36.html
- https://cwe.mitre.org/data/definitions/477.html
- https://cwe.mitre.org/data/definitions/480.html
- https://cwe.mitre.org/data/definitions/51.html
- https://cwe.mitre.org/data/definitions/57.html
- https://cwe.mitre.org/data/definitions/59.html
- https://cwe.mitre.org/data/definitions/65.html
- https://cwe.mitre.org/data/definitions/668.html
- https://cwe.mitre.org/data/definitions/74.html
- https://cwe.mitre.org/data/definitions/87.html