CVE-2021-39162

Incorrect handling of H2 GOAWAY + SETTINGS frames

HIGH
8.6
CVSS Score
Published: September 9, 2021 at 10:05 PM UTC
Updated: June 17, 2026 at 04:03 AM UTC
2 products affected across 2 vendorsEnvoyPomerium

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Severity
HIGH8.6
Exploit prediction
EPSS 2%

Description

Pomerium is an open source identity-aware access proxy. Envoy, which Pomerium is based on, can abnormally terminate if an H/2 GOAWAY and SETTINGS frame are received in the same IO event. This can lead to a DoS in the presence of untrusted *upstream* servers. 0.15.1 contains an upgraded envoy binary with this vulnerability patched. If only trusted upstreams are configured, there is not substantial risk of this condition being triggered.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.18.41.19.0
Affected range stops below 1.18.4, so it looks safe — our inference, not a vendor statement
v < 0.15.10.15.0
Affected range stops below 0.15.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

CVSS

8.6HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-754

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