CVEvulnerability

CVE-2020-10932

4.7 MEDIUM Published 2020-04-15 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2020-04-15
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
4.7 MEDIUM — CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS 2.0 ([email protected])
1.9 LOW — AV:L/AC:M/Au:N/C:P/I:N/A:N
Weaknesses
CWE-203, CWE-327

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 configurations

• arm mbed tls (>= 2.7.0 < 2.7.15) • trustedfirmware mbed tls (>= 2.16.0 < 2.16.6) • fedoraproject fedora 31 • fedoraproject fedora 32 • debian debian linux 10.0

Related

Weakness · CWE (2)

  • CWE-203 Observable Discrepancy weakness
  • CWE-327 Use of a Broken or Risky Cryptographic Algorithm weakness

References