Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In affected versions envoy’s procedure for resetting a HTTP/2 stream has O(N^2) complexity, leading to high CPU utilization when a large number of streams are reset. Deployments are susceptible to Denial of Service when Envoy is configured with high limit on H/2 concurrent streams. An attacker wishing to exploit this vulnerability would require a client opening and closing a large number of H/2 streams. Envoy versions 1.19.1, 1.18.4, 1.17.4, 1.16.5 contain fixes to reduce time complexity of resetting HTTP/2 streams. As a workaround users may limit the number of simultaneous HTTP/2 dreams for upstream and downstream peers to a low number, i.e. 100.
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2021-08-24T20:30:11

Updated: 2024-08-03T23:33:55.854Z

Reserved: 2021-05-12T00:00:00

Link: CVE-2021-32778

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2021-08-24T21:15:09.553

Modified: 2022-06-15T15:49:59.423

Link: CVE-2021-32778

cve-icon Redhat

Severity : Important

Publid Date: 2021-08-24T19:00:00Z

Links: CVE-2021-32778 - Bugzilla