Cybersecurity professionals consider CVE-2023-53785 an immediate threat requiring urgent mitigation.
Status: Deferred
Last updated: 🕙 04 Aug 2026, 10:19 UTC
Originally published on: 🕐 09 Dec 2025, 01:16 UTC
Time between publication and last update: 238 days
CVSS Release: version 3
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Secondary
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVE-2023-53785: In the Linux kernel, the following vulnerability has been resolved: mt76: mt7921: don't assume adequate headroom for SDIO headers mt7921_usb_sdio_tx_prepare_skb() calls mt7921_usb_sdio_write_txwi() and mt7921_skb_add_usb_sdio_hdr(), both of which blindly assume that adequate headroom will be available in the passed skb. This assumption typically is satisfied when the skb was allocated in the net core for transmission via the mt7921 netdev (although even that is only an optimization and is not strictly guaranteed), but the assumption is sometimes not satisfied when the skb originated in the receive path of another netdev and was passed through to the mt7921, such as by the bridge layer. Blindly prepending bytes to an skb is always wrong. This commit introduces a call to skb_cow_head() before the call to mt7921_usb_sdio_write_txwi() in mt7921_usb_sdio_tx_prepare_skb() to ensure that at least MT_SDIO_TXD_SIZE + MT_SDIO_HDR_SIZE bytes can be pushed onto the skb. Without this fix, I can trivially cause kernel panics by bridging an MT7921AU-based USB 802.11ax interface with an Ethernet interface on an Intel Atom-based x86 system using its onboard RTL8169 PCI Ethernet adapter and also on an ARM-based Raspberry Pi 1 using its onboard SMSC9512 USB Ethernet adapter. Note that the panics do not occur in every system configuration, as they occur only if the receiving netdev leaves less headroom in its received skbs than the mt7921 needs for its SDIO headers. Here is an example stack trace of this panic on Raspberry Pi OS Lite 2023-02-21 running kernel 6.1.24+ [1]: skb_panic from skb_push+0x44/0x48 skb_push from mt7921_usb_sdio_tx_prepare_skb+0xd4/0x190 [mt7921_common] mt7921_usb_sdio_tx_prepare_skb [mt7921_common] from mt76u_tx_queue_skb+0x94/0x1d0 [mt76_usb] mt76u_tx_queue_skb [mt76_usb] from __mt76_tx_queue_skb+0x4c/0xc8 [mt76] __mt76_tx_queue_skb [mt76] from mt76_txq_schedule.part.0+0x13c/0x398 [mt76] mt76_txq_schedule.part.0 [mt76] from mt76_txq_schedule_all+0x24/0x30 [mt76] mt76_txq_schedule_all [mt76] from mt7921_tx_worker+0x58/0xf4 [mt7921_common] mt7921_tx_worker [mt7921_common] from __mt76_worker_fn+0x9c/0xec [mt76] __mt76_worker_fn [mt76] from kthread+0xbc/0xe0 kthread from ret_from_fork+0x14/0x34 After this fix, bridging the mt7921 interface works fine on both of my previously problematic systems. [1] https://github.com/raspberrypi/firmware/tree/5c276f55a4b21345cd4d6200a504ee991851ff7a
The exploitability of CVE-2023-53785 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
With low attack complexity and no required privileges, CVE-2023-53785 is an easy target for cybercriminals. Organizations should prioritize immediate mitigation measures to prevent unauthorized access and data breaches.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2023-53785, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2023-53785, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
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