CVE-2021-43825 - CVE House
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Status published Medium CVE-2021-43825

Use-after-free in Envoy

Vulnerability Description

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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

Affected Vendor

Affected Software

envoy
Vulnerable Versions:
< 1.18.6, >= 1.19.0, < 1.19.3, >= 1.20.0, < 1.20.2, >= 1.21.0, < 1.21.1

Timeline

Official Publish: February 22nd, 2022
Last Modified: April 23rd, 2025
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:L

Weaknesses (CWE)