CVE-2025-38131 – This CVE describes a use-after-free vulnerabili... (How to Fix)

Q: What is the severity of CVE-2025-38131?

CVE-2025-38131 has a CVSS score of 7.8 (HIGH). This CVE describes a use-after-free vulnerability in the Linux kernel's CoreSight subsystem where race conditions between configuration activation/deactivation and module unloading can lead to accessing freed memory. This affects Linux systems using CoreSight debugging/tracing functionality, potentially allowing local attackers to crash the system or execute arbitrary code.

📋 TL;DR

This CVE describes a use-after-free vulnerability in the Linux kernel's CoreSight subsystem where race conditions between configuration activation/deactivation and module unloading can lead to accessing freed memory. This affects Linux systems using CoreSight debugging/tracing functionality, potentially allowing local attackers to crash the system or execute arbitrary code.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not explicitly stated in CVE description, but patches are available in stable kernel trees.

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ✅ No

Notes: Only affects systems with CoreSight subsystem enabled and accessible. CoreSight is typically used for ARM processor debugging/tracing and may not be enabled by default on all systems.

📦 What is this software?

Debian Linux by Debian

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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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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...

Learn more about Linux Kernel →

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...

Learn more about Linux Kernel →

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...

Learn more about Linux Kernel →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Local privilege escalation to kernel-level code execution, complete system compromise, or kernel panic causing denial of service.

🟠

Likely Case

Kernel crash or system instability when CoreSight configurations are manipulated while modules are being loaded/unloaded.

🟢

If Mitigated

Limited to denial of service if exploit fails or system has additional protections like kernel address space layout randomization (KASLR).

🌐 Internet-Facing: LOW - Requires local access to the system's CoreSight configuration interface.

🏢 Internal Only: MEDIUM - Local attackers with access to CoreSight sysfs interface could exploit this vulnerability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires race condition timing and access to CoreSight configuration interface. No public exploits known at this time.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patches available in stable kernel trees via git commits referenced in CVE

Vendor Advisory: https://git.kernel.org/stable/c/31028812724cef7bd57a51525ce58a32a6d73b22

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing fixes. 2. Check kernel commit history for patches. 3. Reboot system after kernel update.

🔧 Temporary Workarounds

Disable CoreSight subsystem

linux

Prevent exploitation by disabling CoreSight functionality if not required

echo 0 > /sys/kernel/debug/tracing/events/enable
Remove coresight modules from kernel if built as modules

Restrict sysfs access

linux

Limit access to CoreSight configuration interface

chmod 600 /sys/kernel/debug/tracing/events/coresight/*
setfacl -m u:root:rwx /sys/kernel/debug/tracing/events/coresight/*

🧯 If You Can't Patch

Restrict user access to CoreSight sysfs interface to trusted users only
Monitor system for unexpected CoreSight configuration changes or module loading/unloading

🔍 How to Verify

Check if Vulnerable:

Check kernel version and verify if CoreSight subsystem is active: lsmod | grep coresight

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits or check if CoreSight configuration race conditions are prevented

📡 Detection & Monitoring

Log Indicators:

Kernel oops messages related to CoreSight
Unexpected module unloading of coresight modules
System crashes when manipulating debug/tracing configurations

Network Indicators:

None - local vulnerability only

SIEM Query:

kernel: *coresight* AND (panic OR oops OR segfault)

📊 Metadata

CVE ID: CVE-2025-38131

CVSS v3 Score: 7.8 (HIGH)

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

CWE: CWE-416

EPSS Score: 0.02% exploit probability (4.3th percentile)

Published: July 3, 2025

Last Updated: December 17, 2025

🔗 References

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