CVE-2019-13629: MatrixSSL 4.2.1 and earlier contains a timing side channel in ECDSA signature generation

Q: How do I fix CVE-2019-13629?

matrixssl: upgrade to newer than 4.2.1. Exact commands for each OS are on this page.

Q: Is CVE-2019-13629 being exploited?

CVE-2019-13629 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2019-13629 affect?

CVE-2019-13629 affects matrixssl. Severity is medium (CVSS 5.9). 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

Q: How urgent is CVE-2019-13629?

Priority 43/100. Remotely exploitable, no login, no user action

This month

MEDIUM 5.9REMOTEUPGRADE

CVE-2019-13629 is a medium-severity flaw (CVSS 5.9) affecting matrixssl. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	1.2% (top 31%)
CISA exploited list	No
Weakness	CWE-203, CWE-327
Published	2019-10-03
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: matrixssl

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2019-10-03 14:15 UTCPublished CVE record published
2026-06-17 02:17 UTCUpdated Record last modified

matrixssl matrixssl UPGRADE

Affected: <= 4.2.1

Fixed in: newer than 4.2.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy matrixssl || rpm -q matrixssl || matrixssl --version

2. UPGRADE to newer than 4.2.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade matrixssl

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade matrixssl

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2019-13629?

matrixssl: upgrade to newer than 4.2.1. Exact commands for each OS are on this page.

Is CVE-2019-13629 being exploited?

CVE-2019-13629 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2019-13629 affect?

CVE-2019-13629 affects matrixssl. Severity is medium (CVSS 5.9). 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

How urgent is CVE-2019-13629?

Priority 43/100. Remotely exploitable, no login, no user action

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References

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