CVE-2025-38495

What it actually does

The allocated HID report buffer is one byte too small when the report ID is unused, so low-level transport drivers that write a leading 0 byte overwrite adjacent memory instead of having the expected eight guaranteed bytes.

Why it matters to the business

Linux systems handling HID input devices face elevated risk of kernel memory corruption that can lead to crashes, denial of service, or local privilege escalation; the issue affects a widely used kernel component with high ecosystem prevalence and appears in lists of campaigns by espionage and financially motivated actors, increasing urgency for patching despite low EPSS.

How an attack unfolds

An attacker with local access crafts or supplies a HID report that lacks a report ID; the undersized buffer causes the transport layer to write the required leading zero outside the allocation, corrupting kernel structures and enabling privilege escalation chains observed in related Linux kernel flaws exploited by Advanced Spyware Campaign and 2024 Zero-Day Exploitation Campaigns.

How to fix it

Update the Linux kernel to the commit 7228e36c7875e4b035374cf68ca5e44dffa596b2 or later stable releases that contain this fix; rebuild and deploy the updated kernel across all affected systems; prioritize systems exposed to untrusted HID devices or that match the profile of campaigns listed under related privilege-escalation CVEs.

How to confirm the fix worked

Confirm the running kernel contains commit 7228e36c7875e4b035374cf68ca5e44dffa596b2 by checking git log or kernel version strings; test HID device enumeration and report handling with both report-ID and report-ID-less devices to ensure the buffer size is now correct; monitor for absence of related oops or memory-corruption traces.

Typical attack path

1. Obtain local code execution or user-level access on a vulnerable Linux system
2. Trigger HID report allocation through a device or userspace program that omits the report ID
3. Force the low-level transport driver to write the reserved leading zero byte into the undersized buffer
4. Corrupt adjacent kernel memory to hijack control flow or data structures
5. Escalate privileges or achieve persistence as seen in related kernel exploitation campaigns

How to detect it

Search kernel logs and audit trails for HID report allocation failures, buffer-overrun oops messages, or unexpected crashes involving hid-core or transport drivers; correlate with process activity that interacts with /dev/hidraw or evdev nodes; review for indicators tied to the listed espionage and ransomware-adjacent campaigns that targeted similar kernel flaws.

What your security team should do

• Immediately schedule kernel updates to the fixed commit for all production Linux hosts
• Harden systems that process untrusted HID input by restricting device attachment via udev or kernel parameters until patched
• Add kernel version checks to vulnerability scanners and asset inventories
• Review logs for prior signs of related kernel exploitation attempts listed in threat actor campaigns