CVE-2020-10932

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

15/04/2020

Last modified:

03/03/2023

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.

Impact

Vector 3.x

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N CVSS v3.1 Severity and Metrics:

Base Score: 4.70 MEDIUM
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

Attack Vector (AV): Local
Attack Complexity (AC): High
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): None
Availability (A): None

Base Score 3.x

4.70

Severity 3.x

MEDIUM

Vector 2.0

AV:L/AC:M/Au:N/C:P/I:N/A:N CVSS v2.0 Severity and Metrics:

Base Score: 1.90 LOW
Vector: AV:L/AC:M/Au:N/C:P/I:N/A:N

Attack Vector (AV): Local
Attack Complexity (AC): Medium
Authentication (Au): None
Confidentiality (C): Physical
Integrity (I): None
Availability (A): None

Base Score 2.0

1.90

Severity 2.0

LOW

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:arm:mbed_tls::::::::	2.7.0 (including)	2.7.15 (excluding)
cpe:2.3:a:arm:mbed_tls::::::::	2.16.0 (including)	2.16.6 (excluding)
cpe:2.3:o:fedoraproject:fedora:31:::::::*
cpe:2.3:o:fedoraproject:fedora:32:::::::*
cpe:2.3:o:debian:debian_linux:10.0:::::::*

To consult the complete list of CPE names with products and versions, see this page

CVE-2020-10932

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools