CVE-2024-37880
The Kyber reference implementation before 9b8d306, when compiled by LLVM Clang through 18.x with some common optimization options, has a timing side channel that allows attackers to recover an ML-KEM 512 secret key in minutes.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.70%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
The Kyber reference implementation before 9b8d306, when compiled by LLVM Clang through 18.x with some common optimization options, has a timing side channel that allows attackers to recover an ML-KEM 512 secret key in minutes. This occurs because poly_frommsg in poly.c does not prevent Clang from emitting a vulnerable secret-dependent branch.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 0.70% probability · 51th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-203
- Affected
- pq-crystals/kyber
- Source
- cve@mitre.org
References
- https://github.com/antoonpurnal/clangoverExploit
- https://github.com/pq-crystals/kyber/commit/9b8d30698a3e7449aeb34e62339d4176f11e3c6cPatch
- https://news.ycombinator.com/item?id=40577486Not Applicable
- https://pqshield.com/pqshield-plugs-timing-leaks-in-kyber-ml-kem-to-improve-pqc-implementation-maturity/Exploit, Third Party Advisory
- https://twitter.com/purnaltoon/status/1797644696568959476Exploit
- https://github.com/antoonpurnal/clangoverExploit
- https://github.com/pq-crystals/kyber/commit/9b8d30698a3e7449aeb34e62339d4176f11e3c6cPatch
- https://news.ycombinator.com/item?id=40577486Not Applicable
- https://pqshield.com/pqshield-plugs-timing-leaks-in-kyber-ml-kem-to-improve-pqc-implementation-maturity/Exploit, Third Party Advisory
- https://twitter.com/purnaltoon/status/1797644696568959476Exploit
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.