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CVE-2021-36647

MEDIUM

4.7

Description

Use of a Broken or Risky Cryptographic Algorithm in the function mbedtls_mpi_exp_mod() in lignum.c in Mbed TLS Mbed TLS all versions before 3.0.0, 2.27.0 or 2.16.11 allows attackers with access to precise enough timing and memory access information (typically an untrusted operating system attacking a secure enclave such as SGX or the TrustZone secure world) to recover the private keys used in RSA.

CVE Details

CVSS v3.1 Score4.7

SeverityMEDIUM

CVSS VectorCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

Attack VectorLOCAL

ComplexityHIGH

Privileges RequiredLOW

User InteractionNONE

Published1/17/2023

Last Modified11/3/2025

Sourcenvd

Honeypot Sightings0

Affected Products

arm:mbed_tls

Weaknesses (CWE)

CWE-327CWE-327

References

https://github.com/ARMmbed/mbedtls/releases/(cve@mitre.org)

https://kouzili.com/Load-Step.pdf(cve@mitre.org)

https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1(cve@mitre.org)

https://github.com/ARMmbed/mbedtls/releases/(af854a3a-2127-422b-91ae-364da2661108)

https://kouzili.com/Load-Step.pdf(af854a3a-2127-422b-91ae-364da2661108)

https://lists.debian.org/debian-lts-announce/2025/06/msg00034.html(af854a3a-2127-422b-91ae-364da2661108)

https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1(af854a3a-2127-422b-91ae-364da2661108)

IOC Correlations

No correlations recorded

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