Home/CVE/Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions of Envoy a
CVE

CVE-2021-43826

Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions of Envoy a

Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions of Envoy a crash occurs when configured for :ref:upstream tunneling <envoy_v3_api_field_extensions.filters.network.tcp_proxy.v3.TcpProxy.tunneling_config> and the downstream connection disconnects while the upstream connection or http/2 stream is still being established. There are no workarounds for this issue.

Users are advised to upgrade.

HIGH · CVSS 7.5 EPSS 0.00095
Schedule remediation
  • SSVC automatable: yes - attacks can be scripted at scale
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-416Use After Free
▤

Affected Products & Versions

4
envoyproxy envoy< 1.18.6
envoyproxy envoy>= 1.19.0 and < 1.19.3
envoyproxy envoy>= 1.20.0 and < 1.20.2
envoyproxy envoy>= 1.21.0 and < 1.21.1
▣

Scoring & Timeline

7.5
HIGH · CVSS v3.1 · security-advisories@github.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD22 Feb 2022 · 11:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
yes
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

2
rhsaRHSA-2022:1276Important
rhsaRHSA-2022:1275Important
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://github.com/envoyproxy/envoy/commit/ce0ae309057a216aba031aff81c445c90c6ef145PatchThird Party Advisory
https://github.com/envoyproxy/envoy/security/advisories/GHSA-cmx3-fvgf-83mfIssue TrackingThird Party Advisory
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