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.

Published: 2021-12-07 Last update: 2026-06-05 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-36133 is rated Low Risk (34.3/100): CVSS High severity, with low exploitation likelihood (EPSS 0.06%). 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-2021-36133

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 2025-11-30 0.04% 0.06% +0.01%
2 2025-11-21 0.05% 0.04% -0.01%
3 2025-11-18 — 0.05% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-36133

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.1 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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: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:N)
Service keeps running; no real outage angle.
 1.8 5.2 [email protected]
3.6 2.0 LOW
AV:L/AC:L/Au:N/C:P/I:P/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 3.9 4.9 [email protected]

Weakness enumeration for CVE-2021-36133

OS Trackers for CVE-2021-36133

vendor priority summary link
debian unimportant CVE-2021-36133 unimportant priority: Debian including 1 source packages (optee-os), 3 status rows across 3 suites (forky, sid, trixie): open 3. https://security-tracker.debian.org/tracker/CVE-2021-36133
ubuntu medium CVE-2021-36133 medium priority: Ubuntu including 1 source packages (optee-os), 7 status rows across 7 suites (focal, jammy, noble, oracular, plucky, questing, upstream): DNE 3, ignored 2, needs-triage 2. https://ubuntu.com/security/CVE-2021-36133

Affected software / configurations for CVE-2021-36133

Vendor Product Version Raw CPE
trustedfirmware op-tee — cpe:2.3:o:trustedfirmware:op-tee:-:*:*:*:*:*:*:*

References for CVE-2021-36133

cvelogic Threat Intelligence