What’s Vulnerable › Vulnerabilities

CVE-2019-18222

• Severity: medium (CVSS 4.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-01-23 · updated 2026-06-17
• Weakness: CWE-203

Description

The ECDSA signature implementation in ecdsa.c in Arm Mbed Crypto 2.1 and Mbed TLS through 2.19.1 does not reduce the blinded scalar before computing the inverse, which allows a local attacker to recover the private key via side-channel attacks.

Affected products

• Arm Mbed Crypto: before 3.0.0 — fixed in 3.0.0
• mbedtls: before 2.7.13; from 2.8.0 before 2.16.4; from 2.17.0 before 2.20.0 — fixed in 2.16.4, 2.20.0, 2.7.13
• Debian Linux: 10.0
• Fedoraproject Fedora: 30, 31

How to fix

Upgrade to a fixed version: Arm Mbed Crypto 3.0.0; mbedtls 2.16.4, 2.20.0, 2.7.13. Check the vendor advisory for mitigations.

References

• https://lists.debian.org/debian-lts-announce/2022/12/msg00036.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A3GWQNONS7GRORXZJ7MOJFUEJ2ZJ4OUW/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NGDACU65MYZXXVPQP2EBHUJGOR4RWLVY/
• https://tls.mbed.org/tech-updates/security-advisories
• https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2019-12
• https://lists.debian.org/debian-lts-announce/2022/12/msg00036.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A3GWQNONS7GRORXZJ7MOJFUEJ2ZJ4OUW/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NGDACU65MYZXXVPQP2EBHUJGOR4RWLVY/
• https://tls.mbed.org/tech-updates/security-advisories
• https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2019-12

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