CVE-2021-36154

Name: CVE-2021-36154
Creator: NVD / NIST
Published: 2021-07-09T12:15:08.097+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 2.08%

Last modified Jun 17, 2026

CVE-2021-36154 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. HTTP2ToRawGRPCServerCodec in gRPC Swift 1.1.1 and earlier allows remote attackers to deny service via the delivery of many small messages within a single HTTP/2 frame, leading to Uncontrolled Recursion and stack consumption.. EPSS estimates a 2.08% chance of exploitation in the next 30 days.

Description

HTTP2ToRawGRPCServerCodec in gRPC Swift 1.1.1 and earlier allows remote attackers to deny service via the delivery of many small messages within a single HTTP/2 frame, leading to Uncontrolled Recursion and stack consumption.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

2.08%

79.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-674

Affected Software

Vendor	Product	Versions
Linuxfoundation	Grpc Swift	1.0.0
Linuxfoundation	Grpc Swift	1.1.0
Linuxfoundation	Grpc Swift	1.1.1

References

https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35274Mailing List, Third Party Advisory
https://github.com/grpc/grpc-swift/releasesRelease Notes, Third Party Advisory
https://github.com/grpc/grpc-swift/security/advisories/GHSA-4rhq-vq24-88gwThird Party Advisory
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35274Mailing List, Third Party Advisory
https://github.com/grpc/grpc-swift/releasesRelease Notes, Third Party Advisory
https://github.com/grpc/grpc-swift/security/advisories/GHSA-4rhq-vq24-88gwThird Party Advisory

Timeline

Published: Jul 9, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-36154?

How severe is CVE-2021-36154?

CVE-2021-36154 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 2.08% probability of exploitation in the next 30 days.

How do I fix CVE-2021-36154?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-36154?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST