Is CVE-2021-32780 in the CISA KEV catalog?

No. CVE-2021-32780 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-32780?

CVE-2021-32780 has a CVSS v3 base score of 8.6 (HIGH).

What is the EPSS score for CVE-2021-32780?

CVE-2021-32780 has an EPSS score of 1.23% (65th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-32780?

Upgrade envoy to 1.18.4 or later.

CVE & CISA-KEV Catalog

CVE-2021-32780

HIGH

8.6

CVSS v3

NVD

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.

CWE-754

How to fix

Remediation Available

envoyNVD

Affected:>= 1.18.0, < 1.18.4Fixed in:1.18.4CVE-2021-32780derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeChanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Exploit Intelligence

1.23%probability of exploitation in 30 days

65thpercentile

Moderate risk: more likely to be exploited than 65% of all known CVEs.

References

Vendor Advisory1

envoyproxy.io

Third-Party Advisory1

github.com

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.