CVE-2021-32780

Incorrect handling of H/2 GOAWAY followed by SETTINGS frames

Description

Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In affected versions Envoy transitions a H/2 connection to the CLOSED state when it receives a GOAWAY frame without any streams outstanding. The connection state is transitioned to DRAINING when it receives a SETTING frame with the SETTINGS_MAX_CONCURRENT_STREAMS parameter set to 0. Receiving these two frames in the same I/O event results in abnormal termination of the Envoy process due to invalid state transition from CLOSED to DRAINING. A sequence of H/2 frames delivered by an untrusted upstream server will result in Denial of Service in the presence of untrusted **upstream** servers. Envoy versions 1.19.1, 1.18.4 contain fixes to stop processing of pending H/2 frames after connection transition to the CLOSED state.

Category

8.6
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.08%
Vendor Advisory envoyproxy.io
Affected: envoyproxy envoy
Published at:
Updated at:

References

Link Tags
https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history vendor advisory
https://github.com/envoyproxy/envoy/security/advisories/GHSA-j374-mjrw-vvp8 third party advisory

Frequently Asked Questions

What is the severity of CVE-2021-32780?
CVE-2021-32780 has been scored as a high severity vulnerability.
How to fix CVE-2021-32780?
To fix CVE-2021-32780, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-32780 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-32780 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-32780?
CVE-2021-32780 affects envoyproxy envoy.
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