Synced 16 Jun 2026 15:24 UTC Account
← All products

CVE-2021-43825

MEDIUM severity · CVSS 6.1 · Use-after-free
6.1CVSS MEDIUM

Summary

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 & exploitability

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionRequired
Confidentiality impactNone
Integrity impactLow
Availability impactLow
Exploit probability (EPSS)1%

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

Affected products we track (1)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: https://github.com/envoyproxy/envoy/commit/148de954ed3585d8b4298b424aa24916d0de6136 ↗