CVE-2023-4020: An unvalidated input in a library function responsible for communicating between secure and non-secure memory

This month

CRITICAL 9.0UPGRADE

CVE-2023-4020 is a critical-severity flaw (CVSS 9.0) affecting gecko software development kit. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity

A fixed release or distro patch exists.

Risk facts

CVSS score	9.0 (Critical)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 53%)
CISA exploited list	No
Weakness	CWE-125, CWE-787
Published	2023-12-15
Last modified	2026-06-17

Publisher (CNA): Silicon Labs · Vendor: silabs

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-12-15 21:15 UTCPublished CVE record published
2026-06-17 06:36 UTCUpdated Record last modified

silabs gecko software development kit UPGRADE

Affected: >= 1.0.0 and < 4.4.0

Fixed in: 4.4.0

Safe to downgrade to: a release before 1.0.0

1. Check installed version

apt-cache policy gecko-software-development-kit || rpm -q gecko-software-development-kit || gecko-software-development-kit --version

2. UPGRADE to 4.4.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade gecko-software-development-kit

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade gecko-software-development-kit

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.0.0 (Debian / Ubuntu)

apt-cache madison gecko-software-development-kit sudo apt install gecko-software-development-kit=<VERSION_BEFORE_1.0.0> sudo apt-mark hold gecko-software-development-kit

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list gecko-software-development-kit sudo dnf downgrade gecko-software-development-kit-<VERSION_BEFORE_1.0.0> sudo dnf versionlock add gecko-software-development-kit

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2023-4020?

gecko software development kit: upgrade to 4.4.0. Exact commands for each OS are on this page.

Is CVE-2023-4020 being exploited?

CVE-2023-4020 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-4020 affect?

CVE-2023-4020 affects gecko software development kit. Severity is critical (CVSS 9.0). 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 regio

How urgent is CVE-2023-4020?

Priority 43/100. Critical severity

Related CVEs

CVE-2024-22473 MEDIUM 6.8 UPGRADE TRNG is used before initialization by ECDSA signing driver when exiting EM2/EM3 on Virtual Secure Vault (VSE)
CVE-2024-0240 MEDIUM 6.5 UPGRADE A memory leak in the Silicon Labs' Bluetooth stack for EFR32 products may cause memory to be exhausted when se
CVE-2023-6387 HIGH 7.5 UPGRADE A potential buffer overflow exists in the Bluetooth LE HCI CPC sample application in the Gecko SDK which may r
CVE-2023-5138 MEDIUM 6.8 UPGRADE Glitch detection is not enabled by default for the CortexM33 core in Silicon Labs secure vault high parts EFx3
CVE-2023-4280 CRITICAL 9.3 UPGRADE An unvalidated input in Silicon Labs TrustZone implementation in v4.3.x and earlier of the Gecko SDK allows an

References

← Back to latest CVEs