Excessive Iteration in envoy - CVE-2021-32778

Vulnerability identifier: #VU56147

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2021-32778

CWE-ID: CWE-834

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to the Envoy is configured with high limit on H/2 concurrent streams. A remote attacker can cause a denial of service condition on the target system. 

envoy
servicemesh-proxy (Red Hat package)
servicemesh-operator (Red Hat package)
servicemesh (Red Hat package)
servicemesh-prometheus (Red Hat package)
servicemesh-ratelimit (Red Hat package)
servicemesh-grafana (Red Hat package)
Istio
OpenShift Service Mesh

Install updates from vendor's website.

envoy - addressed in versions 1.16.5, 1.17.4, 1.18.4, 1.19.1
servicemesh-proxy (Red Hat package) - update to 2.1.0-13.el8
servicemesh-operator (Red Hat package) - update to 2.1.0-4.el8
servicemesh (Red Hat package) - update to 2.1.0-5.el8
Istio - addressed in versions 1.9.8, 1.10.4, 1.11.1
servicemesh-prometheus (Red Hat package) - update to 2.23.0-1.el8
OpenShift Service Mesh - update to 2.1.0
servicemesh-ratelimit (Red Hat package) - update to 2.1.0-1.el8
servicemesh-grafana (Red Hat package) - update to 7.2.1-2.el8

• https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history
• https://github.com/envoyproxy/envoy/security/advisories/GHSA-3xh3-33v5-chcc

• Multiple vulnerabilities in Envoy
• Multiple vulnerabiities in Istio
• Denial of service in Red Hat OpenShift Service Mesh