What’s Vulnerable › Vulnerabilities
CVE-2020-10932
- 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: 2020-04-15 · updated 2026-06-17
- Weakness: CWE-203
Description
An issue was discovered in Arm Mbed TLS before 2.16.6 and 2.7.x before 2.7.15. An attacker that can get precise enough side-channel measurements can recover the long-term ECDSA private key by (1) reconstructing the projective coordinate of the result of scalar multiplication by exploiting side channels in the conversion to affine coordinates; (2) using an attack described by Naccache, Smart, and Stern in 2003 to recover a few bits of the ephemeral scalar from those projective coordinates via several measurements; and (3) using a lattice attack to get from there to the long-term ECDSA private key used for the signatures. Typically an attacker would have sufficient access when attacking an SGX enclave and controlling the untrusted OS.
Affected products
- mbedtls: from 2.7.0 before 2.7.15 — fixed in 2.7.15
- Debian Linux: 10.0
- Fedoraproject Fedora: 31, 32
- TrustedFirmware Mbed TLS: from 2.16.0 before 2.16.6 — fixed in 2.16.6
How to fix
Upgrade to a fixed version: mbedtls 2.7.15; TrustedFirmware Mbed TLS 2.16.6. 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/FCWN5HIF4CJ2LZTOMEBJ7Q4IMMV7ZU2V/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNOS2IIBH5WNJXZUV546PY7666DE7Y3L/
- https://tls.mbed.org/tech-updates/releases/mbedtls-2.16.6-and-2.7.15-released
- https://tls.mbed.org/tech-updates/security-advisories
- https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2020-04
- https://lists.debian.org/debian-lts-announce/2022/12/msg00036.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FCWN5HIF4CJ2LZTOMEBJ7Q4IMMV7ZU2V/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNOS2IIBH5WNJXZUV546PY7666DE7Y3L/
- https://tls.mbed.org/tech-updates/releases/mbedtls-2.16.6-and-2.7.15-released
- https://tls.mbed.org/tech-updates/security-advisories
- https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2020-04
Get alerted when CVE-2020-10932 or the next vulnerability affects your stack