How severe is CVE-2021-36133?

CVE-2021-36133 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-36133 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-36133?

CVE-2021-36133 affects Trustedfirmware Op-tee. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-36133?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-36133 published?

CVE-2021-36133 was published on 2021-12-07 and last updated on 2026-06-17.

CVE-2021-36133

CVE-2021-36133 is a high-severity vulnerability in Trustedfirmware Op-tee with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-732.

Key facts

Severity: High (CVSS 3.x base score 7.1)
CVSS v2: 3.6
EPSS exploit prediction: 0% (17th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-732
Affected product: Trustedfirmware Op-tee
Published: 2021-12-07
Last modified: 2026-06-17

Description

The OPTEE-OS CSU driver for NXP i.MX SoC devices lacks security access configuration for several models, resulting in TrustZone bypass because the NonSecure World can perform arbitrary memory read/write operations on Secure World memory. This involves a DMA capable peripheral.

Frequently asked questions

What is CVE-2021-36133?: The OPTEE-OS CSU driver for NXP i.MX SoC devices lacks security access configuration for several models, resulting in TrustZone bypass because the NonSecure World can perform arbitrary memory read/write operations on Secure World memory. This involves a DMA capable peripheral.
How severe is CVE-2021-36133?: CVE-2021-36133 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-36133 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-36133?: CVE-2021-36133 affects Trustedfirmware Op-tee. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-36133?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-36133 published?: CVE-2021-36133 was published on 2021-12-07 and last updated on 2026-06-17.

References

https://github.com/f-secure-foundry/advisories/blob/master/Security_Advisory-Ref_FSC-HWSEC-VR2021-0001-OP-TEE_TrustZone_bypass.txt

Affected products (1)

cpe:2.3:o:trustedfirmware:op-tee:-:*:*:*:*:*:*:*

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