CVE-2025-38529

Q: What is the severity of CVE-2025-38529?

CVE-2025-38529 has a CVSS score of 7.1 (HIGH). This CVE describes an out-of-bounds bit shift vulnerability in the Linux kernel's comedi aio_iiro_16 driver. An attacker with local access can trigger a kernel panic or potentially execute arbitrary code by providing a malicious IRQ number. This affects systems using the comedi subsystem for data acquisition with the aio_iiro_16 hardware.

7.1 HIGH

Denial of Service

📋 TL;DR

This CVE describes an out-of-bounds bit shift vulnerability in the Linux kernel's comedi aio_iiro_16 driver. An attacker with local access can trigger a kernel panic or potentially execute arbitrary code by providing a malicious IRQ number. This affects systems using the comedi subsystem for data acquisition with the aio_iiro_16 hardware.

💻 Affected Systems

Products:

Linux kernel

Versions: 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 loaded and aio_iiro_16 driver is in use. Most systems don't load this driver by default.

📦 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 panic leading to denial of service, or potential privilege escalation to kernel-level code execution.

🟠

Likely Case

Kernel panic causing system crash and denial of service.

🟢

If Mitigated

No impact if comedi subsystem is not loaded or aio_iiro_16 driver is not in use.

🌐 Internet-Facing: LOW - Requires local access to exploit.

🏢 Internal Only: MEDIUM - Local attackers or malicious users could crash systems or potentially escalate privileges.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: LOW

Exploitation requires local access and ability to interact with comedi device files. The vulnerability is straightforward to trigger once access is obtained.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing the fix commits (43ddd82e6a91913cea1c078e782afd8de60c3a53 and related)

Vendor Advisory: https://git.kernel.org/stable/c/43ddd82e6a91913cea1c078e782afd8de60c3a53

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution. 2. Reboot system to load new kernel. 3. Verify comedi module is not vulnerable by checking kernel version.

🔧 Temporary Workarounds

Disable comedi module

linux

Prevent loading of the vulnerable comedi subsystem

echo 'blacklist comedi' >> /etc/modprobe.d/blacklist.conf
rmmod comedi

Restrict device access

linux

Limit access to comedi device files to prevent exploitation

chmod 600 /dev/comedi*
chown root:root /dev/comedi*

🧯 If You Can't Patch

Ensure comedi subsystem is not loaded (check with lsmod | grep comedi)
Restrict local user access to systems using comedi hardware

🔍 How to Verify

Check if Vulnerable:

Check if comedi module is loaded: lsmod | grep comedi. If loaded and kernel version is unpatched, system is vulnerable.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits or is newer than vulnerable versions. Check with uname -r and compare with distribution security advisories.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in /var/log/kern.log or dmesg
Comedi driver loading/unexpected errors

Network Indicators:

None - local exploitation only

SIEM Query:

EventID: Kernel panic OR Process: comedi-related with suspicious parameters

📊 Metadata

CVE ID: CVE-2025-38529

CVSS v3 Score: 7.1 (HIGH)

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

CWE: CWE-125

EPSS Score: 0.01% exploit probability (2.4th percentile)

Published: August 16, 2025

Last Updated: January 7, 2026

🔗 References

https://git.kernel.org/stable/c/43ddd82e6a91913cea1c078e782afd8de60c3a53 Patch
https://git.kernel.org/stable/c/5ac7c60439236fb691b8c7987390e2327bbf18fa Patch
https://git.kernel.org/stable/c/66acb1586737a22dd7b78abc63213b1bcaa100e4 Patch
https://git.kernel.org/stable/c/955e8835855fed8e87f7d8c8075564a1746c1b4c Patch
https://git.kernel.org/stable/c/a88692245c315bf8e225f205297a6f4b13d6856a Patch
https://git.kernel.org/stable/c/c593215385f0c0163015cca4512ed3ff42875d19 Patch
https://git.kernel.org/stable/c/e0f3c0867d7d231c70984f05c97752caacd0daba Patch
https://git.kernel.org/stable/c/ff30dd3f15f443d2a0085b12ec2cc95d44f35fa7 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

Restrict device access

🧯 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

🔗 Related Vulnerabilities