CVE-2021-43824
Null pointer dereference in envoy
At a glance Severity HIGH 7.5 EPSS EPSS 1.06 % · percentile 64 (2026-10-27) State PUBLISHED Published 2022-02-22 Updated 2025-04-23 Assigner GitHub_M NVD status Modified
Description 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.
Scores Version Score Vector Scored by CVSS 3.1 HIGH 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H GitHub_M CVSS 3.1 HIGH 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H NVD · security-advisories@github.com (Secondary) CVSS 3.1 HIGH 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H NVD · nvd@nist.gov (Primary) CVSS 2.0 MEDIUM 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P NVD · nvd@nist.gov (Primary)
Weaknesses (CWE)
European references
Affected configurations (NVD CPE) cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* < 1.18.6cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* ≥ 1.19.0 < 1.19.3cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* ≥ 1.20.0 < 1.20.2cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* ≥ 1.21.0 < 1.21.1
Affected products Product Versions envoyproxy · envoy affected >= 1.20.0, < 1.20.2 ; affected >= 1.19.0, < 1.19.3 ; affected < 1.18.6 ; affected >= 1.21.0, < 1.21.1
References
Sources