CVE-2026-68985 in Exynos 1280
Summary
by MITRE • 11/05/2026
In the Samsung Exynos NPU driver, improper validation of user input in the ioctl handler can lead to an out-of-bounds write, which causes a denial of service.
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Analysis
by VulDB Data Team • 11/05/2026
The vulnerability resides within the kernel-space implementation of the Neural Processing Unit (NPU) driver for Samsung Exynos processors, specifically affecting the interface used by user-space applications to communicate with the hardware accelerator. This component is critical for offloading machine learning and image processing tasks from the central processor, a feature increasingly common in modern mobile devices and embedded systems. The core technical flaw stems from an improper validation mechanism within the ioctl handler, which serves as the primary entry point for control commands issued by user-space processes. When these commands are received, the driver is responsible for verifying that all parameters provided by the application fall within acceptable bounds before they are processed or passed to the hardware firmware. In this specific instance, the code fails to adequately check array indices, buffer sizes, or pointer offsets against the allocated memory limits defined in the kernel data structures.
This lack of rigorous boundary checking allows a malicious user-space process to craft a specially crafted ioctl request that supplies out-of-bounds values. Upon execution, these invalid parameters cause the driver to write data beyond the boundaries of its intended memory allocation. This results in an out-of-bounds write condition, which is classified under CWE-787 as a buffer overflow vulnerability occurring outside the bounds of a allocated buffer. The immediate operational impact of this flaw is typically a denial of service due to kernel panic or system crash. When the kernel writes to invalid memory addresses, it corrupts critical data structures such as page tables, slab caches, or other kernel objects. This corruption triggers an exception that halts normal operation, forcing the device to reboot or become unresponsive until power-cycled. While out-of-bounds writes can theoretically lead to arbitrary code execution if specific heap grooming techniques are employed, in this context, the primary observed consequence is system instability and service interruption.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1059, specifically Command and Scripting Interpreter interactions at the kernel level, although it manifests primarily as a denial of service rather than direct code execution. It also relates to CWE-20, Improper Input Validation, highlighting the failure to sanitize or verify external data before processing. The severity is heightened by the fact that many ioctl handlers in Linux kernels are accessible to unprivileged users depending on device file permissions, potentially allowing any local application to trigger this condition without requiring elevated privileges initially. This makes it a viable vector for local privilege escalation if combined with other vulnerabilities, though its standalone impact remains focused on availability.
Mitigation strategies must address both the immediate code defect and broader architectural security practices. The primary remediation involves patching the Exynos NPU driver to implement strict bounds checking before any memory access operations are performed within the ioctl handler. Developers should utilize kernel APIs that enforce size limits, such as memcpy_s or equivalent safe string handling functions, and ensure that all user-supplied indices are validated against the maximum allocated dimensions of associated buffers. Additionally, enabling Kernel Hardening features like KASAN (Kernel Address Sanitizer) during development can help detect these out-of-bounds accesses early in the software lifecycle. For system administrators, restricting access to the device node associated with the NPU driver via file permissions limits exposure to untrusted applications. Regularly updating the kernel and vendor-specific drivers is essential to ensure that such input validation flaws are corrected before they can be exploited by malicious actors seeking to disrupt service or destabilize the operating environment.