CVE-2021-24029

Name: CVE-2021-24029
Creator: NVD / NIST
Published: 2021-03-15T22:15:13.53+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.19%

Last modified Jun 17, 2026

CVE-2021-24029 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A packet of death scenario is possible in mvfst via a specially crafted message during a QUIC session, which causes a crash via a failed assertion. Per QUIC specification, this particular message should be treated as a connection error. EPSS estimates a 1.19% chance of exploitation in the next 30 days.

Description

A packet of death scenario is possible in mvfst via a specially crafted message during a QUIC session, which causes a crash via a failed assertion. Per QUIC specification, this particular message should be treated as a connection error. This issue affects mvfst versions prior to commit a67083ff4b8dcbb7ee2839da6338032030d712b0 and proxygen versions prior to v2021.03.15.00.

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

1.19%

63.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Facebook	Mvfst	< 2021-03-13
Facebook	Proxygen	< 2021.03.15.00

References

https://github.com/facebookincubator/mvfst/commit/a67083ff4b8dcbb7ee2839da6338032030d712b0Patch, Third Party Advisory
https://www.facebook.com/security/advisories/cve-2021-24029Vendor Advisory
https://github.com/facebookincubator/mvfst/commit/a67083ff4b8dcbb7ee2839da6338032030d712b0Patch, Third Party Advisory
https://www.facebook.com/security/advisories/cve-2021-24029Vendor Advisory

Timeline

Published: Mar 15, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-24029?

How severe is CVE-2021-24029?

CVE-2021-24029 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.19% probability of exploitation in the next 30 days.

How do I fix CVE-2021-24029?

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-2021-24029?

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

Scan your code now

Source: NVD / NIST