Envoy Proxy Multiple Vulnerabilities

Envoy's RBAC filter improperly concatenates duplicate HTTP headers into comma-separated strings instead of validating each value individually, allowing attackers to bypass "Deny" access control policies through header manipulation. This vulnerability affects Envoy versions prior to 1.34.13, 1.35.8, 1.36.5, and 1.37.1, and public exploit code exists. Patches are available for all affected versions.

Envoy proxy versions prior to 1.37.1, 1.36.5, 1.35.8, and 1.34.13 crash when processing scoped IPv6 addresses through the Utility::getAddressWithPort function, which is invoked by the original_src and dns filters in the data plane. This denial of service vulnerability can be triggered remotely without authentication, and public exploit code exists. No patch is currently available for affected deployments.

Envoy proxy versions before 1.37.1, 1.36.5, 1.35.8, and 1.34.13 contain a use-after-free vulnerability in the HTTP connection manager that allows attackers to trigger denial of service by sending data frames on streams after they have been reset. Public exploit code exists for this vulnerability, and no patch is currently available. The flaw enables filter callbacks to execute on logically cleaned-up streams, potentially causing service disruption or state corruption.

Envoy proxy versions prior to 1.37.1, 1.36.5, 1.35.8, and 1.34.13 can be crashed by an authenticated attacker through improper state cleanup in the rate limit filter when both request and response phase limiting are enabled. When a response phase rate limit request fails, the gRPC client reuses stale internal state from the prior request phase, leading to a use-after-free condition that crashes the proxy. An attacker with network access and valid credentials can exploit this to cause a denial of service against Envoy instances.

Envoy is a high-performance edge/middle/service proxy. [CVSS 5.3 MEDIUM]