CVE-2021-36647 - Vulnerability Details - OpenCVE

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.

No CVSS v4.0

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00033.

Exploitation none

Automatable no

Technical Impact partial

Vendors	Products
Arm	Mbed Tls

Configuration 1 [-]

OR	cpe:2.3:a:arm:mbed_tls::::::::
	cpe:2.3:a:arm:mbed_tls::::::::
	cpe:2.3:a:arm:mbed_tls::::::::

No data.

No data.

Advisories

Source	ID	Title
Debian DLA	DLA-4236-1	mbedtls security update
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.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References

Link	Providers
https://github.com/ARMmbed/mbedtls/releases/
https://kouzili.com/Load-Step.pdf
https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1

History

Tue, 08 Apr 2025 21:15:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

MITRE

Status: PUBLISHED

Assigner: mitre

Published: 2023-01-17T00:00:00.000Z

Updated: 2025-04-08T20:31:32.007Z

Reserved: 2021-07-12T00:00:00.000Z

Link: CVE-2021-36647

Vulnrichment

Updated: 2024-08-04T01:01:58.158Z

NVD

Status : Modified

Published: 2023-01-17T21:15:10.880

Modified: 2025-04-08T21:15:44.210

Link: CVE-2021-36647

Redhat

No data.

OpenCVE Enrichment

No data.

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