CVE-2020-36478

HIGH

Mbed TLS < 2.25.0, < 2.16.9 LTS, < 2.7.18 LTS - Improper Certificate Validation

Title source: llm
STIX 2.1

Description

An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). A NULL algorithm parameters entry looks identical to an array of REAL (size zero) and thus the certificate is considered valid. However, if the parameters do not match in any way, then the certificate should be considered invalid.

References (7)

Core 7
Core References
Mailing List, Third Party Advisory mailing-list
https://lists.debian.org/debian-lts-announce/2021/11/msg00021.html
Mailing List, Third Party Advisory mailing-list
https://lists.debian.org/debian-lts-announce/2022/12/msg00036.html
Exploit, Third Party Advisory
https://github.com/ARMmbed/mbedtls/issues/3629
Release Notes, Third Party Advisory
https://github.com/ARMmbed/mbedtls/releases/tag/v2.16.9
Release Notes, Third Party Advisory
https://github.com/ARMmbed/mbedtls/releases/tag/v2.25.0
Release Notes, Third Party Advisory
https://github.com/ARMmbed/mbedtls/releases/tag/v2.7.18

Scores

CVSS v3 7.5
EPSS 0.0052
EPSS Percentile 67.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Details

CWE
CWE-295
Status published
Products (9)
arm/mbed_tls < 2.7.18
debian/debian_linux 9.0
debian/debian_linux 10.0
siemens/logo\!_cmr2020_firmware < 2.2
siemens/logo\!_cmr2040_firmware < 2.2
siemens/simatic_rtu3000c_firmware
siemens/simatic_rtu3030c_firmware
siemens/simatic_rtu3031c_firmware
siemens/simatic_rtu3041c_firmware
Published Aug 23, 2021
Tracked Since Feb 18, 2026