CVE-2023-4020 | Unvalidated input in Silicon Labs PSA Attestation service leads to secure memory access from non-secure memory

An unvalidated input in a library function responsible for communicating between secure and non-secure memory in Silicon Labs TrustZone implementation allows reading/writing of memory in the secure region of memory from the non-secure region of memory.

Published: 2023-12-15 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-4020 is rated Moderate Risk (50.2/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.20%). Review affected assets and schedule remediation.

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-2023-4020

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 2025-03-17 0.12% 0.20% +0.08%
2 2023-12-20 0.04% 0.12% +0.08%
3 2023-12-16 — 0.04% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-4020

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.0 3.1 CRITICAL
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N 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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
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:N)
Service keeps running; no real outage angle.
 2.5 5.8 [email protected]
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
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:N)
Service keeps running; no real outage angle.
 3.9 5.2 [email protected]

Weakness enumeration for CVE-2023-4020

Affected software / configurations for CVE-2023-4020

Vendor Product Version Raw CPE
silabs gecko_software_development_kit >= 1.0.0, < 4.4.0 cpe:2.3:a:silabs:gecko_software_development_kit:*:*:*:*:*:*:*:*

References for CVE-2023-4020

cvelogic Threat Intelligence