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…
- Published
- Updated
- Reserved
- Assigned by
- mozilla
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.
Timeline
ID reserved
By mozilla
- 1 day later
· 1 day later
Published
- 8 months later
· 8 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Medium6.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L |
| NVDNVD · Modified | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.44% · top 62% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.3.
Weakness
- PK11_Encrypt using CKM_CHACHA20 can reveal plaintext on Intel Sandy Bridge machines
- CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition (opens in a new tab)All about CWE-367 and its CVEs
Affected products
- affected unspecified – < 129
- affected unspecified – < 115.14
- affected unspecified – < 128.1
References (4)
- https://bugzilla.mozilla.org/show_bug.cgi?id=1905691 (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2024-33/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2024-34/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2024-35/ (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2024-7531)Record last updated .