CVE-2021-43825 MEDIUM

CVE-2021-43825: Use-after-free in Envoy

Vendor Envoyproxy
Product envoy
Weakness CWE-416
Published February 22, 2022
Last update April 23, 2025

CVSS base score

6.1/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:L

What the vulnerability does

01Description

Envoy is an open source edge and service proxy, designed for cloud-native applications. Sending a locally generated response must stop further processing of request or response data. Envoy tracks the amount of buffered request and response data and aborts the request if the amount of buffered data is over the limit by sending 413 or 500 responses. However when the buffer overflows while response is processed by the filter chain the operation may not be aborted correctly and result in accessing a freed memory block. If this happens Envoy will crash resulting in a denial of service.

Key dates

02Disclosure timeline

February 22, 2022 CVE published
April 23, 2025 Record updated