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Fencer Intel
medium 4.7

CVE-2019-13628 json

wolfCrypt leaks cryptographic information via timing side channel

published 7y ago modified 4mo ago also GHSA-q95h-vc86-hv77 , PYSEC-2026-1066 , EUVD-2022-4925

cvss
4.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

wolfSSL and wolfCrypt 4.0.0 and earlier (when configured without --enable-fpecc, --enable-sp, or --enable-sp-math) contain a timing side channel in ECDSA signature generation. This allows a local attacker, able to precisely measure the duration of signature operations, to infer information about the nonces used and potentially mount a lattice attack to recover the private key used. The issue occurs because ecc.c scalar multiplication might leak the bit length.

Patch / fix

  • pypi wolfcrypt 4.1.0
  • wolfssl Debian 13, Debian 12 4.1.0+dfsg-1

debian advisories DEBIAN-CVE-2019-13628

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Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 1.2 AV:L/AC:H/Au:N/C:P/I:N/A:N
OSV 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
GitHub 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
pypi wolfcrypt
<4.1.0
4.1.0

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.