HOMEVULNERABILITIESCVE-2021-39206
HIGH

CVE-2021-39206

CWE-863Published: 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, contains two authorization related vulnerabilities CVE-2021-32777 and CVE-2021-32779. This may lead to incorrect routing or authorization policy decisions. With specially crafted requests, incorrect authorization or routing decisions may be made by Pomerium. Pomerium v0.14.8 and v0.15.1 contain an upgraded envoy binary with these vulnerabilities patched. This issue can only be triggered when using path prefix based policy. Removing any such policies should provide mitigation.

NVD Source

Technical Analysis

CVE-2021-39206 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 full integrity compromise (data manipulation), 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
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

Affected Vendors & Products

envoyproxy1 product(s)
envoy
pomerium1 product(s)
pomerium
Source: NVD CPE · 4 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

All References (8)

Quick Facts

CVE IDCVE-2021-39206
CVSS Score8.6 / 10
SeverityHIGH
WeaknessCWE-863
CISA KEVNo
Affected2 vendor(s)
PublishedSep 9, 2021

Related CVEs (CWE-863)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2021-39206 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.