CVE-2021-32781: Use After Free
First published: Tue Aug 24 2021(Updated: )
Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In affected versions after Envoy sends a locally generated response it must stop further processing of request or response data. However when local response is generated due the internal buffer overflow while request or response is processed by the filter chain the operation may not be stopped completely and result in accessing a freed memory block. A specifically constructed request delivered by an untrusted downstream or upstream peer in the presence of extensions that modify and increase the size of request or response bodies resulting in a Denial of Service when using extensions that modify and increase the size of request or response bodies, such as decompressor filter. Envoy versions 1.19.1, 1.18.4, 1.17.4, 1.16.5 contain fixes to address incomplete termination of request processing after locally generated response. As a workaround disable Envoy's decompressor, json-transcoder or grpc-web extensions or proprietary extensions that modify and increase the size of request or response bodies, if feasible.
Credit: security-advisories@github.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Envoyproxy Envoy | >=1.16.0<1.16.5 | |
| Envoyproxy Envoy | >=1.17.0<1.17.4 | |
| Envoyproxy Envoy | >=1.18.0<1.18.4 | |
| Envoyproxy Envoy | =1.19.0 |
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Reference Links
Frequently Asked Questions
What is CVE-2021-32781?
CVE-2021-32781 is a vulnerability in Envoy, an open-source L7 proxy and communication bus, which allows further processing of request or response data after a locally generated response is sent.
What is the severity of CVE-2021-32781?
The severity of CVE-2021-32781 is high with a CVSS score of 7.5.
How does CVE-2021-32781 affect Envoy?
CVE-2021-32781 affects versions of Envoy from 1.16.0 to 1.16.5, 1.17.0 to 1.17.4, 1.18.0 to 1.18.4, and 1.19.0.
How can I fix CVE-2021-32781 in Envoy?
To fix CVE-2021-32781, upgrade Envoy to version 1.19.0 or apply the necessary patches provided by EnvoyProxy.
Where can I find more information about CVE-2021-32781?
More information about CVE-2021-32781 can be found in the EnvoyProxy security advisory: <a href='https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vhv-gp9v-42qv'>https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vhv-gp9v-42qv</a>
- collector/nvd-index
- vendor/envoyproxy
- canonical/envoyproxy envoy
- version/envoyproxy envoy/1.16.0
- version/envoyproxy envoy/1.17.0
- version/envoyproxy envoy/1.18.0
- version/envoyproxy envoy/1.19.0