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

CVE-2021-43824

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

Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions a crafted request crashes Envoy when a CONNECT request is sent to JWT filter configured with regex match. This provides a denial of service attack vector.

The only workaround is to not use regex in the JWT filter. Users are advised to upgrade.

HIGH · CVSS 7.5 EPSS 0.00125
Schedule remediation
  • SSVC automatable: yes - attacks can be scripted at scale
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-476NULL Pointer Dereference
▤

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/9371333230b1a6e1be2eccf4868771e11af6253aPatchThird Party Advisory
https://github.com/envoyproxy/envoy/security/advisories/GHSA-vj5m-rch8-5r2pIssue TrackingThird Party Advisory
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