Security readout for executives and security teams
Plain-English summary
CVE-2021-29258 is a remotely triggerable crash in Envoy 1.14.0. A malformed HTTP/2 Metadata condition can hit an internal assertion and stop the proxy process, creating a denial-of-service risk for services depending on Envoy for ingress, service mesh, or gateway traffic.
Executive priority
Treat this as an availability risk for systems that depend on Envoy 1.14.0. It is not sourced as actively exploited, but remote crash conditions can still disrupt customer-facing services and internal platforms.
Technical view
The CVE describes an empty HTTP/2 METADATA map causing a reachable assertion in Envoy 1.14.0. The impact described is crash behavior, not data theft or code execution. The source bundle does not provide CVSS, CWE, affected version ranges beyond 1.14.0, or patch version details.
Likely exposure
Exposure is most likely where Envoy 1.14.0 handles remotely supplied HTTP/2 traffic. The provided data does not identify downstream distributions, service mesh products, or a broader affected-version range.
Exploitation context
The CVE text says the crash is remotely exploitable. KEV is false, and the supplied sources do not show active exploitation in the wild or public weaponization evidence.
Researcher notes
Key gaps remain: no CVSS vector, no CWE, no confirmed affected range beyond Envoy 1.14.0, and no patch version in the provided bundle. Do not assume impact beyond denial of service without vendor advisory confirmation.
Mitigation direction
- Inventory Envoy deployments and confirm whether version 1.14.0 is present.
- Check Envoy’s GitHub advisory for official upgrade or mitigation guidance.
- Prioritize internet-facing gateways and service-mesh edge proxies.
- Apply vendor-recommended updates through normal change control.
- Monitor proxy availability and restart patterns until remediation is complete.
Validation and detection
- Confirm running Envoy versions from deployment manifests or asset inventory.
- Identify Envoy instances accepting HTTP/2 traffic from untrusted networks.
- Review logs and crash reports for assertion failures or unexpected restarts.
- Check vendor advisory status before closing the remediation ticket.
- Document any compensating controls if immediate upgrade is not possible.
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.
CVE-2021-29258 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://blog.envoyproxy.io/CVE reference · x_refsource_MISC
- https://github.com/envoyproxy/envoy-setec/pull/230CVE reference · x_refsource_MISC
- https://github.com/envoyproxy/envoy/releases/tag/v1.14.0CVE reference · x_refsource_MISC
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-xw4q-6pj2-5gfgCVE 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.