ZephyrProject Zephyr up to 4.4.1 Time-aware GPIO timeaware_gpio_handlers.c z_vrfy_tgpio_pin_read_ts_ec timestamp/event_count privileges management

Summaryinfo

A vulnerability described as very critical has been identified in ZephyrProject Zephyr up to 4.4.1. Affected by this vulnerability is the function z_vrfy_tgpio_pin_read_ts_ec of the file drivers/timeaware_gpio/timeaware_gpio_handlers.c of the component Time-aware GPIO. The manipulation of the argument timestamp/event_count results in privileges management. This vulnerability is known as CVE-2026-17052. Attacking locally is a requirement. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in ZephyrProject Zephyr up to 4.4.1. It has been classified as very critical. Affected is the function z_vrfy_tgpio_pin_read_ts_ec of the file drivers/timeaware_gpio/timeaware_gpio_handlers.c of the component Time-aware GPIO. The manipulation of the argument timestamp/event_count with an unknown input leads to a privileges management vulnerability. CWE is classifying the issue as CWE-269. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

The Time-aware GPIO syscall verification handler z_vrfy_tgpio_pin_read_ts_ec() in drivers/timeaware_gpio/timeaware_gpio_handlers.c validated only the port device object and passed the caller-supplied timestamp and event_count output pointers to the driver without a K_SYSCALL_MEMORY_WRITE() check. The other handlers in the same file (z_vrfy_tgpio_port_get_time(), z_vrfy_tgpio_port_get_cycles_per_second()) already performed that check, so the omission left one syscall unguarded. tgpio_pin_read_ts_ec() is declared __syscall, so with CONFIG_USERSPACE=y an unprivileged user-mode thread that has been granted access to the TGPIO device object can invoke it with arbitrary pointer values. tgpio_intel_read_ts_ec() in drivers/timeaware_gpio/timeaware_gpio_intel.c bounds-checks only the pin index and then unconditionally performs timestamp = ... and event_count = ..., executing two 8-byte stores in supervisor mode at addresses chosen by the user-mode caller. The result is a write-what-where primitive that crosses the userspace/kernel boundary: the target address is fully attacker-chosen and the stored values are the hardware time-capture and event-counter register contents. Corrupting kernel data structures this way can escalate the calling thread to supervisor privilege or crash the system; the device-object permission required is a narrow capability that is not intended to confer any kernel-memory access. The fix adds the two missing K_SYSCALL_MEMORY_WRITE() validations before the driver call. Exposure is narrow in practice. Only builds with CONFIG_USERSPACE=y and CONFIG_TIMEAWARE_GPIO=y compile the affected file, and from v3.6.0 onward the file additionally referenced a relocated header (<zephyr/syscall_handler.h>) and removed Z_SYSCALL_* macros, so such a configuration failed to build until those were repaired after v4.4.0. Downstream trees that locally corrected that breakage, and v3.5.0 builds where it did not exist, are the exposed population.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-17052 since 07/24/2026. The exploitability is told to be easy. Local access is required to approach this attack. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/21/2026). This vulnerability is assigned to T1068 by the MITRE ATT&CK project.

Upgrading to version 4.4.2 eliminates this vulnerability. Applying the patch 26264fffc17c2174319394ffa274af3f6efdc221 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Project Management Software

Vendor

• ZephyrProject

Name

• Zephyr

Version

• 4.4.0
• 4.4.1

CPE 2.3info

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CPE 2.2info

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