CVE-2024-7531

Name: CVE-2024-7531
Creator: NVD / NIST
Published: 2024-08-06T13:15:57.787+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.41%

Last modified Jun 17, 2026

CVE-2024-7531 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Calling `PK11_Encrypt()` in NSS using CKM_CHACHA20 and the same buffer for input and output can result in plaintext on an Intel Sandy Bridge processor. In Firefox this only affects the QUIC header protection feature when the connection is using the ChaCha20-Poly1305 cipher suite. EPSS estimates a 0.41% chance of exploitation in the next 30 days.

Description

Calling `PK11_Encrypt()` in NSS using CKM_CHACHA20 and the same buffer for input and output can result in plaintext on an Intel Sandy Bridge processor. In Firefox this only affects the QUIC header protection feature when the connection is using the ChaCha20-Poly1305 cipher suite. The most likely outcome is connection failure, but if the connection persists despite the high packet loss it could be possible for a network observer to identify packets as coming from the same source despite a network path change. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, and Firefox ESR < 128.1.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.41%

32.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-367

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 129.0
Mozilla	Firefox Esr	< 115.14.0
Mozilla	Firefox Esr	128.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1905691Issue Tracking, Permissions Required
https://www.mozilla.org/security/advisories/mfsa2024-33/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2024-34/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2024-35/Vendor Advisory

Timeline

Published: Aug 6, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2024-7531?

How severe is CVE-2024-7531?

CVE-2024-7531 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.41% probability of exploitation in the next 30 days.

How do I fix CVE-2024-7531?

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-2024-7531?

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

Scan your code now

Source: NVD / NIST