CVE-2023-37366 in Exynos
Summary
by MITRE • 09/14/2026
An issue was discovered in Samsung Exynos Mobile Processor, Automotive Processor, and Modem Exynos 9810, Exynos 9610, Exynos 9820, Exynos 980, Exynos 850, Exynos 1080, Exynos 2100, Exynos 2200, Exynos 1280, Exynos 1380, Exynos 1330, Exynos 9110, Exynos W920, Exynos Modem 5123, Exynos Modem 5300, an Exynos Auto T5123. In the Shannon SM Task, improper handling of a loop with an unreachable exit condition cannot guarantee the termination of a required service via a malformed SM message.
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Analysis
by VulDB Data Team • 09/14/2026
The identified vulnerability resides within the System Management (SM) task subsystem of Samsung’s extensive Exynos processor family, encompassing mobile, automotive, and modem variants including models such as the Exynos 9810 through 2200, various mid-range chips like the Exynos 850 and 1380, and specialized modems. This flaw is characterized by an improper handling of a loop structure that possesses an unreachable exit condition when processing malformed System Management messages. In embedded systems architecture, particularly those utilizing Samsung’s Exynos SoCs, the SM task often serves as a critical component for managing hardware resources, power states, and inter-processor communication between the application processor and various co-processors or modems. The security mechanism relies on strict validation of incoming commands to ensure system stability; however, this specific implementation fails to adequately validate input parameters that dictate loop termination logic.
From a technical perspective, the core issue is an infinite loop caused by malformed input data within the SM task handler. When a specially crafted System Management message is received, it triggers a control flow path where the loop condition never evaluates to false due to incorrect state updates or missing boundary checks. This results in the processor becoming stuck in a tight execution cycle that consumes 100 percent of the relevant CPU core’s time slice. Because this occurs within a privileged system task responsible for maintaining essential services, the inability to break out of this loop effectively halts the progression of required operational functions. The service does not crash in the traditional sense but rather hangs indefinitely, leading to a complete denial of availability for any functionality dependent on that specific SM subsystem or its downstream dependencies.
The operational impact of this vulnerability is severe, primarily manifesting as a Denial of Service (DoS) condition. An attacker who can inject malicious System Management messages into the communication channel between processors could trigger this infinite loop remotely if the interface is exposed over network-connected modem interfaces, or locally if they have access to internal buses or debug ports in compromised scenarios. For mobile devices and automotive systems based on these Exynos chips, such a hang would result in device unresponsiveness, loss of connectivity, or failure of critical safety features in automotive contexts where real-time processing is mandatory. The lack of guaranteed termination means that standard watchdog timers may fail to reset the system if they are configured with timeouts longer than the loop execution time or if the SM task itself manages the watchdog feed mechanism, thereby exacerbating the persistence of the fault state until a hard power cycle is performed by the user.
This vulnerability aligns closely with CWE-835, which describes loops that do not terminate correctly due to logic errors preventing exit condition evaluation. It also relates to CWE-400 regarding uncontrolled resource consumption, as the infinite loop monopolizes processing resources indefinitely. In terms of offensive security frameworks such as MITRE ATT&CK, this flaw facilitates availability impact techniques where an adversary aims to disrupt service rather than steal data or gain persistent access. The attack vector typically involves crafting specific binary payloads that exploit the parsing logic within the SM task handler, targeting the boundary checks and loop counter updates that are insufficiently validated against malicious input lengths or values.
Mitigation strategies must focus on both immediate patching and long-term architectural improvements. Samsung should release firmware updates that enforce strict validation of all inputs received by the Shannon SM Task before they enter processing loops. This includes implementing robust bounds checking, ensuring that loop counters are properly decremented or incremented based on validated input sizes, and adding explicit timeout mechanisms within the task itself to force a break from any execution path exceeding a predefined safe duration. Additionally, developers should adopt secure coding practices such as static analysis tools configured to detect unreachable code paths and infinite loops during the development phase. For end-users and system integrators, applying vendor-provided security patches is critical, while in automotive or industrial deployments, implementing hardware-level watchdog timers with independent power domains can help mitigate the impact by forcing a reset if the software hangs are detected externally.