PT-2026-57570 · Zephyrproject · Zephyr
Published
2026-07-12
·
Updated
2026-07-12
·
CVE-2026-10668
CVSS v3.1
2.4
Low
| Vector | AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
The Nuvoton NuMaker HSUSBD USB device-controller driver (drivers/usb/udc/udc numaker.c) armed the control Data IN stage unconditionally (base->CEPTXCNT = len in numaker hsusbd ep trigger). Because the HSUSBD hardware cannot disarm a control Data IN already armed for a previous transfer, a USB host that cancels an in-flight control transfer (timeout) and then issues a new SETUP packet can drive the driver out of sync: stale data may be transmitted in the new transfer and the control endpoint can become permanently stuck NAK'ing every subsequent control transfer.
A malicious or buggy host (physical/adjacent attacker driving the bus) can repeatedly cancel-and-re-SETUP to wedge the device's USB control endpoint, denying service to the device's USB function (the device stops enumerating/responding on the control pipe) until a USB reset or re-plug. The flaw is an availability-only denial of service; the FIFO copy loops (bounded by net buf length and the hardware BUFFULL flag) and the net buf lifecycle are independent of the arming desync, so there is no out-of-bounds access, use-after-free, or information leak.
The fix monitors the IN-token and new-SETUP events (k event) and only arms control Data IN when an IN token is present and no new SETUP has arrived, cancelling the current transfer on a new SETUP. Affects boards using the Nuvoton NuMaker HSUSBD controller (CONFIG UDC NUMAKER with DT HAS NUVOTON NUMAKER HSUSBD ENABLED); shipped in v4.4.0.
Fix
Resource Exhaustion
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Weakness Enumeration
Related Identifiers
Affected Products
Zephyr