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Fencer Vulns
medium 4.1

CVE-2024-1544 json

ECDSA nonce bias caused by truncation

published 2024-08-27 2 y ago modified 2026-07-25 3 mo ago also EUVD-2024-17291 , GHSA-grjj-54gm-q5vf , JLSEC-2026-682

cvss
4.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 28%
public exploits
0
none known

Summary

Generating the ECDSA nonce k samples a random number r and then truncates this randomness with a modular reduction mod n where n is the order of the elliptic curve. Meaning k = r mod n. The division used during the reduction estimates a factor q_e by dividing the upper two digits (a digit having e.g. a size of 8 byte) of r by the upper digit of n and then decrements q_e in a loop until it has the correct size. Observing the number of times q_e is decremented through a control-flow revealing side-channel reveals a bias in the most significant bits of k. Depending on the curve this is either a negligible bias or a significant bias large enough to reconstruct k with lattice reduction methods. For SECP160R1, e.g., we find a bias of 15 bits.

Patch / fix

  • julia wolfSSL_jll 5.7.2+0
  • wolfssl wolfssl 5.7.2
  • wolfssl Debian 13 5.7.2-0.1

debian advisories DEBIAN-CVE-2024-1544

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.1 CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N
NVD 3.1 4.9 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
OSV 3.1 4.9 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
julia wolfSSL_jll
<5.7.2+0
5.7.2+0

Affected products

  • wolfSSL wolfSSL

Classification

Weakness

References

Sources

Fencer Vulns 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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.