CVE-2020-27212

STMicroelectronics STM32L4 devices through 2020-10-19 have incorrect access control. The flash read-out protection (RDP) can be degraded from RDP level 2 (no access via debug interface) to level 1 (limited access via debug interface) by injecting a fault during the boot phase.

Published: 2021-05-21 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-27212 is rated Low Risk (39.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.14%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-27212

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-04 0.23% 0.14% -0.09%
2 2026-05-03 0.10% 0.23% +0.14%
3 2025-11-21 0.10%

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-27212

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.0 3.1 HIGH
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.0 5.9 [email protected]
4.4 2.0 MEDIUM
AV:L/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
3.4 6.4 [email protected]

Weakness enumeration for CVE-2020-27212

Affected software / configurations for CVE-2020-27212

Vendor Product Version Raw CPE
st stm32cubel4_firmware <= 1.16.0 cpe:2.3:o:st:stm32cubel4_firmware:*:*:*:*:*:*:*:*

References for CVE-2020-27212

cvelogic Threat Intelligence