CVE-2020-10932

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.

How to fix CVE-2020-10932

To remediate CVE-2020-10932, upgrade the affected package to a fixed version below.

• —upgrade to 2.16.6-r0 or later
• —upgrade to 2.16.9-0.1 or later

Is CVE-2020-10932 being exploited?

Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.

Affected packages (2)

• from 0, < 2.16.6-r0
• from 0, < 2.16.9-0.1

CVSS scores

References (2)

• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2020-10932
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2020-10932