An issue was discovered in Envoy 1.12.0. An untrusted remote client may send an HTTP header (such as Host) with whitespace after the header content. Envoy will treat "header-value " as a different string from "header-value" so for example with the Host header "example.com " one could bypass "example.com" matchers.
| Software | From | Fixed in |
|---|---|---|
| envoyproxy / envoy | - | 1.12.1.x |