CVE Vulnerability

CVE-2021-32778

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.

5 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 10 / Impact : 2.9

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact PARTIAL

Scope

7.5 /10

CVSS v3.0 : HIGH

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history Release Notes Vendor Advisory
https://github.com/envoyproxy/envoy/security/advisories/GHSA-3xh3-33v5-chcc Third Party Advisory
Configurations

Configuration 1

cpe:2.3:a:envoyproxy:envoy:1.19.0:*:*:*:*:*:*:*
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
Information

Published : 2021-08-24 09:15

Updated : 2022-06-15 03:49

NVD link : CVE-2021-32778

Mitre link : CVE-2021-32778

Products Affected
No products.
CWE
CWE-834