optee_os: Improper Handling of Exceptional Conditions
CVE-2025-46733 is a high-severity improper handling of exceptional conditions vulnerability in optee_os from OP-TEE, with a CVSS 3.1 base score of 7.9 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected optee_os versions: = 4.5.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of optee_os you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- LowLimited modification of data is possible.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L. Scored by CNA (github.com).
Official description
OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. In version 4.5.0, using a specially crafted tee-supplicant binary running in REE userspace, an attacker can trigger a panic in a TA that uses the libutee Secure Storage API. Many functions in libutee, specifically those which make up the Secure Storage API, will panic if a system call returns an unexpected return code. This behavior is mandated by the TEE Internal Core API specification. However, in OP-TEE’s implementation, return codes of secure storage operations are passed through unsanitized from the REE tee-supplicant, through the Linux kernel tee-driver, through the OP-TEE kernel, back to libutee. Thus, an attacker with access to REE userspace, and the ability to stop tee-supplicant and replace it with their own process (generally trivial for a root user, and depending on the way permissions are set up, potentially available even to less privileged users) can run a malicious tee-supplicant process that responds to storage requests with unexpected response codes, triggering a panic in the requesting TA. This is particularly dangerous for TAs built with `TA_FLAG_SINGLE_INSTANCE` (corresponding to `gpd.ta.singleInstance` and `TA_FLAG_INSTANCE_KEEP_ALIVE` (corresponding to `gpd.ta.keepAlive`). The behavior of these TAs may depend on memory that is preserved between sessions, and the ability of an attacker to panic the TA and reload it with a clean memory space can compromise the behavior of those TAs. A critical example of this is the optee_ftpm TA. It uses the kept alive memory to hold PCR values, which crucially must be non-resettable. An attacker who can trigger a panic in the fTPM TA can reset the PCRs, and then extend them PCRs with whatever they choose, falsifying boot measurements, accessing sealed data, and potentially more. The impact of this issue depends significantly on the behavior of affected TAs. For some, it could manifest as a denial of service, while for others, like the fTPM TA, it can result in the disclosure of sensitive data. Anyone running the fTPM TA is affected, but similar attacks may be possible on other TAs that leverage the Secure Storage API. A fix is available in commit 941a58d78c99c4754fbd4ec3079ec9e1d596af8f.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Exceptional Conditions
The product does not handle or incorrectly handles an exceptional condition.
More Improper Handling of Exceptional Conditions vulnerabilities (CWE-755)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in optee_os
- 7.8 High severity
- 7.5 High severity
- 8.7 High severity
- 8.8 High severity
Recent Improper Handling of Exceptional Conditions vulnerabilities
- 8.8 High severity
- 7.5 High severity
- 7.1 High severity
- 7.5 High severity
- 8.0 High severity
- 7.5 High severity
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