Vulnerability in Arm Mbed TLS
CVE-2020-36478
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.
Vulnerability class: Improper Certificate Validation
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.011 (64.4th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 64.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.012 · newest: 0.011 · change: -0.001
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/ARMmbed/mbedtls/releases/tag/v2.25.0 (Third Party Advisory, Release Notes)
- github.com/ARMmbed/mbedtls/releases/tag/v2.16.9 (Third Party Advisory, Release Notes)
- github.com/ARMmbed/mbedtls/releases/tag/v2.7.18 (Third Party Advisory, Release Notes)
- github.com/ARMmbed/mbedtls/issues/3629 (Exploit, Third Party Advisory)
- cert-portal.siemens.com/productcert/pdf/ssa-756638.pdf (Patch, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2021/11/msg00021.html (mailing-list, Mailing List, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2022/12/msg00036.html (mailing-list, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-36478?
- CVE-2020-36478 is a high-severity vulnerability in Arm Mbed TLS, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2021-08-23.
- How severe is CVE-2020-36478?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2020-36478 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.