Security readout for executives and security teams
Plain-English summary
A specific Pomerium release can crash because its embedded Envoy proxy mishandles certain HTTP/2 control frames from an upstream server. The business impact is service availability: affected gateways could abnormally terminate. Risk is mainly relevant where Pomerium connects to upstream servers that are not fully trusted.
Executive priority
Prioritize remediation for internet-facing or business-critical Pomerium deployments that proxy to untrusted upstreams. Trusted-upstream-only deployments appear lower urgency, but the affected version should still be removed during normal patching.
Technical view
CVE-2021-39162 affects Pomerium versions >=0.15.0 and <0.15.1. Envoy can abnormally terminate when an HTTP/2 GOAWAY and SETTINGS frame are received in the same IO event. The issue is classified as CWE-754 and has CVSS 3.1 score 8.6, driven by high availability impact.
Likely exposure
Exposure is limited to Pomerium 0.15.0 deployments before 0.15.1, especially when configured with untrusted upstream servers. Sources state trusted-only upstream configurations do not carry substantial risk of this condition being triggered.
Exploitation context
The source bundle does not cite active exploitation, and KEV is false. The stated attack condition involves an untrusted upstream server triggering abnormal Envoy termination through HTTP/2 frame handling. No exploit maturity, public exploit, or real-world incident evidence is provided.
Researcher notes
The vulnerability is inherited from Envoy and surfaced in Pomerium’s advisory. The key exposure variable is upstream trust, not only external client reachability. Available sources identify the patched Pomerium release but do not provide exploitation evidence beyond the described crash condition.
Mitigation direction
- Upgrade Pomerium to version 0.15.1 or later.
- Confirm the deployed build includes the patched upgraded Envoy binary.
- Avoid routing affected Pomerium instances to untrusted upstream servers.
- Review Pomerium and Envoy vendor advisories for environment-specific guidance.
Validation and detection
- Inventory Pomerium versions and flag any >=0.15.0 and <0.15.1.
- Identify affected deployments connected to untrusted upstream servers.
- Confirm post-upgrade Pomerium reports version 0.15.1 or later.
- Review service logs for unexplained Envoy or Pomerium abnormal terminations.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-754: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-39162 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H3.94Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.6HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://groups.google.com/g/envoy-announce/c/5xBpsEZZDfE/m/wD05NZBbAgAJCVE reference · x_refsource_MISC
- https://github.com/pomerium/pomerium/security/advisories/GHSA-gjcg-vrxg-xmgvCVE reference · x_refsource_CONFIRM
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-j374-mjrw-vvp8CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Check for Unusual or Exceptional Conditions
Improper Check for Unusual or Exceptional Conditions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.