CVE-2024-7531

CVE-2024-7531 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-367.

Key facts

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.

Frequently asked questions

What is CVE-2024-7531?
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.
How severe is CVE-2024-7531?
CVE-2024-7531 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2024-7531 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-7531?
CVE-2024-7531 primarily affects Mozilla Firefox. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-7531?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-7531 have an EU (EUVD) identifier?
Yes. CVE-2024-7531 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-48438.
When was CVE-2024-7531 published?
CVE-2024-7531 was published on 2024-08-06 and last updated on 2026-06-17.

References

Affected products (3)

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