PT-2020-6618 · Mbed Tls+2 · Mbed Tls+2

Peter Kolbus · Published 2020-12-02 · Updated 2025-08-21 · CVE-2020-36475

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Mbed TLS versions prior to 2.25.0 Mbed TLS versions prior to 2.16.9 LTS Mbed TLS versions prior to 2.7.18 LTS

Description The issue is related to the mbedtls mpi exp mod function in Mbed TLS, which lacks a limit on the size of data during calculations. This allows a remote attacker to cause a denial of service by supplying overly large parameters, particularly when generating Diffie-Hellman key pairs.

Recommendations For Mbed TLS versions prior to 2.25.0, update to version 2.25.0 or later to resolve the issue. For Mbed TLS versions prior to 2.16.9 LTS, update to version 2.16.9 LTS or later to resolve the issue. For Mbed TLS versions prior to 2.7.18 LTS, update to version 2.7.18 LTS or later to resolve the issue. As a temporary workaround, consider restricting the size of parameters supplied to the mbedtls mpi exp mod function to prevent overly large inputs.

Fix

DoS

Weakness Enumeration

CWE-131

Related Identifiers

ALT-PU-2020-3502

ALT-PU-2021-2234

ALT-PU-2025-10462

BDU:2022-01649

CVE-2020-36475

DLA-2826-1

DLA-3249-1

Affected Products

Alt Linux

Astra Linux

Mbed Tls

References · 21

• https://osv.dev/vulnerability/DLA-2826-1 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2020-36475 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2020-36475 · Security Note
• https://ubuntu.com/security/CVE-2020-36475 · Vendor Advisory
• https://cert-portal.siemens.com/productcert/pdf/ssa-756638.pdf · Patch
• https://security-tracker.debian.org/tracker/CVE-2020-36475 · Vendor Advisory
• https://osv.dev/vulnerability/DLA-3249-1 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2020-36475 · Vendor Advisory
• https://bdu.fstec.ru/vul/2022-01649 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2020-36475 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2020-36475 · Security Note
• https://github.com/ARMmbed/mbedtls/releases/tag/v2.7.18 · Note
• https://github.com/ARMmbed/mbedtls/releases/tag/v2.25.0 · Note
• https://github.com/ARMmbed/mbedtls/releases/tag/v2.16.9 · Note
• https://github.com/ARMmbed/mbedtls/commit/9246d041500b96fb0694cbda1d833e420696827e · Note