CVE-2021-36647

Published Jan 17, 2023 CVSS 3.1 · 4.7 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4236-1 mbedtls security update
EUVD EUVD EUVD-2021-23243 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.
History
Type Values Removed Values Added
First Time appeared Trustedfirmware
Trustedfirmware mbed Tls
CPEs cpe:2.3:a:trustedfirmware:mbed_tls:*:*:*:*:*:*:*:*
Vendors & Products Trustedfirmware
Trustedfirmware mbed Tls
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Nov 3, 2025, 7:26 PM
Reserved
Jul 12, 2021, 12:00 AM
Status
Modified
Published
Jan 17, 2023, 9:15 PM
Modified
Jun 17, 2026, 3:58 AM