CVE-2020-10932
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…
Does this matter?
Lower severity and a low EPSS score (0.25%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 4.7 MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 0.25% probability · 16th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-203, CWE-327
- Affected
- arm/mbed tls · trustedfirmware/mbed tls · fedoraproject/fedora · debian/debian linux
- Source
- cve@mitre.org
References
- https://lists.debian.org/debian-lts-announce/2022/12/msg00036.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FCWN5HIF4CJ2LZTOMEBJ7Q4IMMV7ZU2V/Mailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNOS2IIBH5WNJXZUV546PY7666DE7Y3L/Mailing List, Third Party Advisory
- https://tls.mbed.org/tech-updates/releases/mbedtls-2.16.6-and-2.7.15-releasedRelease Notes
- https://tls.mbed.org/tech-updates/security-advisoriesVendor Advisory
- https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2020-04Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2022/12/msg00036.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FCWN5HIF4CJ2LZTOMEBJ7Q4IMMV7ZU2V/Mailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNOS2IIBH5WNJXZUV546PY7666DE7Y3L/Mailing List, Third Party Advisory
- https://tls.mbed.org/tech-updates/releases/mbedtls-2.16.6-and-2.7.15-releasedRelease Notes
- https://tls.mbed.org/tech-updates/security-advisoriesVendor Advisory
- https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2020-04Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.