CVE-2020-36423
An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext...
An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.
- Record
CVE-2020-36423- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Weakness
- CWE-319
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.
- Record
CVE-2020-36423- Updated
- 2026-11-02
EUVDEUVD-2020-23951 No score
An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.
- Record
EUVD-2020-23951- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-x2rg-rvm2-p2f9
An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext...
An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.
- Record
GHSA-x2rg-rvm2-p2f9- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-319
- Updated
- 2026-11-02
OSV
An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.
- Record
CVE-2020-36423- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2020-36423
An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.
- Record
DEBIAN-CVE-2020-36423- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVJLSEC-2025-206
An issue was discovered in Arm Mbed TLS before 2.23.0
An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.
- Record
JLSEC-2025-206- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2020-36423
An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.
- Record
UBUNTU-CVE-2020-36423- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mbedtlsDebian:12 |
before 2.16.9-0.1 | 2.16.9-0.1 |
mbedtlsDebian:13 |
before 2.16.9-0.1 | 2.16.9-0.1 |
mbedtlsDebian:14 |
before 2.16.9-0.1 | 2.16.9-0.1 |
mbedtlsDebian:10 From an advisory covering 18 CVEs |
before 2.16.9-0~deb10u1, plus listed versions 2.16.0-12.16.2-12.16.3-12.16.4-12.16.5-1 |
2.16.9-0~deb10u1 |
MbedTLS_jllJulia |
before 2.16.8+0 | 2.16.8+0 |
mbedtlsUbuntu:16.04:LTS |
All versions, plus listed versions 2.1.2-12.2.0-12.2.1-12.2.1-22.2.1-2ubuntu0.12.2.1-2ubuntu0.22.2.1-2ubuntu0.3 |
None known |
mbedtlsUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 2.5.1-1ubuntu12.6.0-12.7.0-22.8.0-12.8.0-1ubuntu0.1~esm1 |
None known |
mbedtlsUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 2.16.2-12.16.3-12.16.4-1ubuntu22.16.4-1ubuntu2+esm1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-36423 is a high vulnerability (CVSS 7.5) in Arm Mbed Tls, published July 19, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.20%, the 68th percentile. Fixed in mbedtls 2.16.9-0.1.
References
github.com/ARMmbed/mbedtls/releases/tag/v2.16.7
bugs.gentoo.org/730752
lists.debian.org/debian-lts-announce/2022/12/msg00036.html
nvd.nist.gov/vuln/detail/CVE-2020-36423
security-tracker.debian.org/tracker/CVE-2020-36423
ubuntu.com/security/CVE-2020-36423
cve.org/CVERecord?id=CVE-2020-36423