CVE-2025-38478

Q: What is the severity of CVE-2025-38478?

CVE-2025-38478 has a CVSS score of 5.5 (MEDIUM). A kernel memory initialization vulnerability in Linux Comedi subsystem allows reading uninitialized kernel memory when handling certain device instructions. This affects systems using Comedi drivers for data acquisition hardware. Attackers could potentially leak sensitive kernel memory contents.

5.5 MEDIUM

📋 TL;DR

A kernel memory initialization vulnerability in Linux Comedi subsystem allows reading uninitialized kernel memory when handling certain device instructions. This affects systems using Comedi drivers for data acquisition hardware. Attackers could potentially leak sensitive kernel memory contents.

💻 Affected Systems

Products:

Linux kernel with Comedi subsystem

Versions: Linux kernel versions before the fix commits (specific versions vary by distribution)

Operating Systems: Linux distributions with vulnerable kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if Comedi subsystem is enabled/loaded and specific hardware drivers are in use. Most standard Linux installations are not affected.

📦 What is this software?

Debian Linux by Debian

View all CVEs affecting Debian Linux →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

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⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel memory disclosure leading to information leakage, potential privilege escalation if combined with other vulnerabilities, or system instability/crashes.

🟠

Likely Case

Information disclosure of kernel memory contents, which could reveal sensitive data or aid in further exploitation.

🟢

If Mitigated

Limited impact due to need for local access and specific Comedi hardware/drivers being used.

🌐 Internet-Facing: LOW - Requires local access to system and Comedi hardware/drivers.

🏢 Internal Only: MEDIUM - Local attackers could exploit this to leak kernel memory if Comedi is in use.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access, knowledge of Comedi subsystem, and specific hardware/drivers. No public exploits known at this time.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in kernel commits: 020eed5681d0f9bced73970368078a92d6cfaa9c, 13e4d9038a1e869445a996a3f604a84ef52fe8c4, 46d8c744136ce2454aa4c35c138cc06817f92b8e, 673ee92bd2d31055bca98a1d96b653f5284289c4, 6f38c6380c3b38a05032b8881e41137385a6ce02

Vendor Advisory: https://git.kernel.org/stable/c/

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commits. 2. Check with your distribution for specific patched kernel versions. 3. Reboot system after kernel update.

🔧 Temporary Workarounds

Disable Comedi module

linux

Unload Comedi kernel module if not required

sudo rmmod comedi
sudo modprobe -r comedi

Blacklist Comedi module

linux

Prevent Comedi module from loading at boot

echo 'blacklist comedi' | sudo tee /etc/modprobe.d/blacklist-comedi.conf

🧯 If You Can't Patch

Restrict local user access to systems with Comedi hardware
Implement strict access controls and monitor for suspicious Comedi-related system calls

🔍 How to Verify

Check if Vulnerable:

Check if Comedi module is loaded: lsmod | grep comedi. If loaded, check kernel version against patched versions.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits or is newer than vulnerable versions. Check with distribution vendor for specific patched versions.

📡 Detection & Monitoring

Log Indicators:

Unusual Comedi device access patterns
Multiple failed Comedi ioctl calls
Kernel oops or warnings related to Comedi

Network Indicators:

Not applicable - local vulnerability

SIEM Query:

Process monitoring for comedi-related system calls from unusual users or processes

📊 Metadata

CVE ID: CVE-2025-38478

CVSS v3 Score: 5.5 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-908

EPSS Score: 0.02% exploit probability (4th percentile)

Published: July 28, 2025

Last Updated: December 23, 2025

🔗 References

https://git.kernel.org/stable/c/020eed5681d0f9bced73970368078a92d6cfaa9c Patch
https://git.kernel.org/stable/c/13e4d9038a1e869445a996a3f604a84ef52fe8f4 Patch
https://git.kernel.org/stable/c/46d8c744136ce2454aa4c35c138cc06817f92b8e Patch
https://git.kernel.org/stable/c/673ee92bd2d31055bca98a1d96b653f5284289c4 Patch
https://git.kernel.org/stable/c/6f38c6380c3b38a05032b8881e41137385a6ce02 Patch
https://git.kernel.org/stable/c/c42116dc70af6664526f7aa82cf937824ab42649 Patch
https://git.kernel.org/stable/c/d3436638738ace8f101af7bdee2eae1bc38e9b29 Patch
https://git.kernel.org/stable/c/fe8713fb4e4e82a4f91910d9a41bf0613e69a0b9 Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Third Party Advisory,Mailing List
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Third Party Advisory,Mailing List

📋 TL;DR

💻 Affected Systems

📦 What is this software?

Debian Linux by Debian

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

⚠️ Risk & Real-World Impact

Worst Case

Likely Case

If Mitigated

🎯 Exploit Status

🛠️ Fix & Mitigation

✅ Official Fix

Instructions:

🔧 Temporary Workarounds

Disable Comedi module

Blacklist Comedi module

🧯 If You Can't Patch

🔍 How to Verify

Check if Vulnerable:

Check Version:

Verify Fix Applied:

📡 Detection & Monitoring

Log Indicators:

Network Indicators:

SIEM Query:

📊 Metadata

🔗 References

📤 Share & Export

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