Envoy is a cloud-native edge/middle/service proxy. Prior to versions 1.34.1, 1.33.3, 1.32.6, and 1.31.8, Envoys URI template matcher incorrectly excludes the * character from a set of valid characters in the URI path. As a result URI path containing the * character will not match a URI template expressions. This can result in bypass of RBAC rules when configured using the uri_template permissions. This vulnerability is fixed in Envoy versions v1.34.1, v1.33.3, v1.32.6, v1.31.8. As a workaround, configure additional RBAC permissions using url_path with safe_regex expression.
A regular expression is overly restrictive, which prevents dangerous values from being detected.