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Fencer Intel
high 7.5

CVE-2024-37880 json

The Kyber reference implementation before 9b8d306, when compiled by LLVM Clang through 18.x with some common optimization options, has a ti…

published 2y ago modified 4mo ago also EUVD-2024-36864

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits
0
none known

Summary

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.

Patch / fix

  • pq-crystals kyber 2024-06-03

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
2y ago

Exploit prediction

0.70% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • pqshield.com https://pqshield.com/pqshield-plugs-timing-leaks-in-kyber-ml-kem-to-improve-pqc-implementation-maturity/ referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/antoonpurnal/clangover referenced PoC, tagged "exploit" by a source, unverified
  • twitter.com https://twitter.com/purnaltoon/status/1797644696568959476 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

  • pq-crystals kyber

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.