CVE-2026-94023 in ThreadX
Summary
by MITRE • 10/20/2026
A ThreadX module reaches a kernel object's delete service through the Module Manager's dispatch layer, which asked one question about the pointer: does the object lie outside the module's own code and data. That is the policy for *using* an object, and using an object a module does not own is supported and intended — `txm_module_object_pointer_get_extended` searches the system's created objects by name and hands back objects the application created and objects other modules created, so that a module can send to a shared queue, take a shared semaphore or get a shared mutex.
Destroying one of those is not sharing it. A module could name any object it had a pointer to and have the privileged dispatcher delete it.
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Analysis
by VulDB Data Team • 10/20/2026
The vulnerability described involves a critical logic error within the ThreadX real-time operating system's Module Manager, specifically concerning the handling of kernel objects across module boundaries. The core issue stems from an insufficient validation check during the deletion process for kernel objects accessed through the dispatch layer. While the existing policy correctly permits modules to utilize shared resources such as queues, semaphores, and mutexes created by other modules or the application itself, it fails to distinguish between using a resource and destroying one. The system allows any module that holds a pointer to a kernel object to request its deletion via the privileged dispatcher, provided only that the object does not reside within the calling module's own code or data segments. This oversight creates a significant security gap where modules can inadvertently or maliciously terminate resources they do not own, leading to potential system instability and denial of service conditions for other components relying on those objects.
From a technical perspective, this flaw represents an improper access control mechanism regarding resource lifecycle management. The function txm_module_object_pointer_get_extended is designed to facilitate inter-module communication by allowing modules to retrieve pointers to shared objects based on names. This functionality is essential for modular design in embedded systems where components must interact dynamically. However, the subsequent deletion service lacks a corresponding ownership verification step that would ensure only the creator or an explicitly authorized entity can destroy the object. By relying solely on whether the pointer lies outside the caller's memory space as the sole criterion for allowing deletion, the system ignores the fundamental principle of least privilege and proper resource ownership. This allows any module with access to the dispatcher to target objects created by other modules or the main application, effectively bypassing intended isolation boundaries between software components.
The operational impact of this vulnerability is severe in multi-threaded embedded environments where ThreadX is commonly deployed. If a maliciously crafted or compromised module can trigger the deletion of critical kernel objects such as semaphores used for synchronization or queues used for data exchange, it can cause immediate system crashes, deadlocks, or undefined behavior in dependent modules. For instance, if Module A creates a semaphore to coordinate with Module B, and Module C obtains a pointer to that semaphore through shared access mechanisms, Module C could delete the semaphore without authorization. This would leave Module B waiting indefinitely for a signal that will never come, resulting in a denial of service. In safety-critical applications such as automotive control systems or medical devices, such failures can lead to catastrophic consequences due to loss of real-time guarantees and system integrity.
This vulnerability aligns with CWE-284 Improper Access Control, specifically the failure to enforce proper ownership checks before performing destructive operations on shared resources. It also relates to CWE-613 Insufficient Session Expiration or Resource Management in contexts where resource lifecycle is not strictly tied to creator privileges. In terms of MITRE ATT&CK for IoT and embedded systems, this behavior can be categorized under T1499 Endpoint Denial of Service, as an attacker could exploit the flaw to disrupt system availability by deleting essential synchronization primitives. Additionally, it reflects aspects of T1055 Process Injection or Tampering if used in conjunction with other exploits to destabilize the host environment for further exploitation stages.
Mitigation strategies must focus on enforcing strict ownership verification at the kernel object deletion interface. The dispatch layer should be modified to verify that the requesting module is indeed the creator of the target kernel object before allowing the delete operation to proceed. This can be achieved by maintaining a mapping between created objects and their originating modules, ensuring that only the owner or an explicitly designated administrator entity has permission to destroy shared resources. Additionally, implementing role-based access controls within the Module Manager could restrict deletion privileges to specific high-privilege contexts rather than allowing any module with pointer access to perform such actions. Developers should also audit existing codebases for calls to object destruction services and ensure that they are protected by appropriate authorization checks. Regular security reviews of inter-module communication patterns will help identify similar logical flaws in resource management before deployment in production environments.