HOMEVULNERABILITIESCVE-2021-39162
HIGH

CVE-2021-39162

CWE-754Published: September 9, 2021· Updated: Jun 17, 2026

8.6
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-39162 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 8.6.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
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

Affected Vendors & Products

envoyproxy1 product(s)
envoy
pomerium1 product(s)
pomerium
Source: NVD CPE · 3 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://github.com/envoyproxy/envoy/security/advisories/GHSA-j374-mjrw-vvp8
ADVISORYhttps://github.com/pomerium/pomerium/security/advisories/GHSA-gjcg-vrxg-xmgv
ADVISORYhttps://groups.google.com/g/envoy-announce/c/5xBpsEZZDfE/m/wD05NZBbAgAJ
ADVISORYhttps://github.com/envoyproxy/envoy/security/advisories/GHSA-j374-mjrw-vvp8
ADVISORYhttps://github.com/pomerium/pomerium/security/advisories/GHSA-gjcg-vrxg-xmgv
ADVISORYhttps://groups.google.com/g/envoy-announce/c/5xBpsEZZDfE/m/wD05NZBbAgAJ

All References (6)

→
https://github.com/envoyproxy/envoy/security/advisories/GHSA-j374-mjrw-vvp8Third Party Advisory
→
https://github.com/pomerium/pomerium/security/advisories/GHSA-gjcg-vrxg-xmgvThird Party Advisory
→
https://groups.google.com/g/envoy-announce/c/5xBpsEZZDfE/m/wD05NZBbAgAJNot Applicable · Third Party Advisory
→
https://github.com/envoyproxy/envoy/security/advisories/GHSA-j374-mjrw-vvp8Third Party Advisory
→
https://github.com/pomerium/pomerium/security/advisories/GHSA-gjcg-vrxg-xmgvThird Party Advisory
→
https://groups.google.com/g/envoy-announce/c/5xBpsEZZDfE/m/wD05NZBbAgAJNot Applicable · Third Party Advisory

Quick Facts

CVE IDCVE-2021-39162
CVSS Score8.6 / 10
SeverityHIGH
WeaknessCWE-754
CISA KEVNo
Affected2 vendor(s)
PublishedSep 9, 2021

Related CVEs (CWE-754)

CVE-2021-0211
10.0
CVE-2023-48698
9.8
CVE-2020-8986
9.8
CVE-2023-48696
9.8
CVE-2020-10571
9.8
CVE-2024-7826
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-39162 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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