MatrixSSL 4.2.1 and earlier contains a timing side channel in ECDSA signature generation.

published 2019-10-03 7y ago modified 2026-06-17 4mo ago also EUVD-2019-5060

cvss: 5.9; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.2%; EPSS 1.2% chance of exploitation in 30 days, percentile 69%
public exploits: 0; none known

MatrixSSL 4.2.1 and earlier contains a timing side channel in ECDSA signature generation. This allows a local or a remote attacker, able to measure the duration of hundreds to thousands of signing operations, to compute the private key used. The issue occurs because crypto/pubkey/ecc_math.c scalar multiplication leaks the bit length of the scalar.

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Exploit prediction

1.24% chance of exploitation in the next 30 days, higher than 69% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:P/I:N/A:N

Classification

Weakness

CWE-203 Observable Discrepancy
CWE-327 Use of a Broken or Risky Cryptographic Algorithm

References

eprint.iacr.org /2011/232.pdf
not-applicable
tches.iacr.org /index.php/TCHES/article/view/7337
not-applicable
openwall.com /lists/oss-security/2019/10/02/2
mailing-list, third-party-advisory
minerva.crocs.fi.muni.cz /
product

Sources

CVE List CVE-2019-13629
NVD CVE-2019-13629

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