4.6 MEDIUM
- CVSS version (CVSS): 3.1
- Attack Vector (AV): Physical (P)
- Attack Complexity (AC): Low (L)
- Privileges Required (PR): None (N)
- User Interaction (UI): None (N)
- Scope (S): Unchanged (U)
- Confidentiality (C): None (N)
- Integrity (I): None (N)
- Availability (A): High (H)
- Modified Attack Vector (MAV): Physical (P)
- Modified Attack Complexity (MAC): Low (L)
- Modified Privileges Required (MPR): None (N)
- Modified User Interaction (MUI): None (N)
- Modified Confidentiality (MC): None (N)
- Modified Scope (MS): Unchanged (U)
- Modified Integrity (MI): None (N)
- Modified Availability (MA): High (H)
by @LeSuisse Activity log
- Created suggestion
- @LeSuisse dismissed (not in Nixpkgs)
NULL pointer dereference in USB DFU device_next download handler (handle_download)
The USB DFU class implementation in Zephyr's new (experimental) device_next USB device stack contains a NULL pointer dereference in handle_download() (subsys/usb/device_next/class/usbd_dfu.c). The handler computes MIN(setup->wLength, buf->len) and passes buf->data to the image write callback without checking that the buf net_buf pointer is non-NULL. The handler is reached over the USB control endpoint, driven by the USB host. For a DFU_DNLOAD (download) request with no Data OUT stage — notably the zero-length terminating download that the DFU protocol uses to end a firmware transfer — the USB core invokes the class handler with a NULL buffer. After the device has been advanced to the DFU_DNLOAD_IDLE state (by sending one valid download block and a GET_STATUS), a zero-length DFU_DNLOAD reaches handle_download() with buf == NULL, dereferencing it. The result is a NULL+offset read that triggers a fatal CPU fault, i.e. a denial of service (device crash/reset). The attacker is whatever controls the USB host the device is attached to; DFU download support must be enabled with a registered image. There is no memory corruption or information disclosure — impact is limited to availability. The fix adds an explicit if (buf != NULL) guard so the callback receives a zero-length, NULL-data transfer instead of crashing.
References
Affected products
- <4.5.0
Matching in nixpkgs
pkgs.python313Packages.smoke-zephyr
Python utility collection
pkgs.python314Packages.smoke-zephyr
Python utility collection
pkgs.python313Packages.zephyr-python-api
Set of wrappers for Zephyr Scale (TM4J) REST API
pkgs.python314Packages.zephyr-python-api
Set of wrappers for Zephyr Scale (TM4J) REST API
pkgs.python313Packages.zephyr-test-management
Wrappers for both Zephyr Scale and Zephyr Squad (TM4J) REST APIs
Package maintainers
-
@fabaff Fabian Affolter <mail@fabian-affolter.ch>
-
@Steinhagen Viorel-Cătălin Răpițeanu <rapiteanu.catalin@gmail.com>