Denial of service.
|CVSS Impact Score
|1.3 to 1.3.4
Envoy, and subsequently Istio, are vulnerable to the following DoS attack.
An infinite loop can be triggered in Envoy if the option
continue_on_listener_filters_timeout is set to
True. This has been the case for Istio since the introduction of the Protocol Detection feature in Istio 1.3
A remote attacker may trivially trigger that vulnerability, effectively exhausting Envoy’s CPU resources and causing a denial-of-service attack.
Impact and detection
Both Istio gateways and sidecars are vulnerable to this issue. If you are running one of the affected releases, your cluster is vulnerable.
Workaround: The exploitation of that vulnerability can be prevented by customizing Istio installation (as described in installation options ), using Helm to override the following options:
--set pilot.env.PILOT_INBOUND_PROTOCOL_DETECTION_TIMEOUT=0s --set global.proxy.protocolDetectionTimeout=0s
For Istio 1.3.x deployments: update to Istio 1.3.5 or later.
We’d like to remind our community to follow the vulnerability reporting process to report any bug that can result in a security vulnerability.