CVE-2025-38466 – This CVE addresses a Linux kernel vulnerability... (How to Fix)

Q: What is the severity of CVE-2025-38466?

CVE-2025-38466 has a CVSS score of 5.5 (MEDIUM). This CVE addresses a Linux kernel vulnerability where uprobes (user-space probes) could be misused to place breakpoints in the middle of instructions or on data within text segments, potentially causing crashes or unintended behavior. The fix requires CAP_SYS_ADMIN privilege for uprobes, affecting Linux systems where unprivileged users could previously use uprobes.

📋 TL;DR

This CVE addresses a Linux kernel vulnerability where uprobes (user-space probes) could be misused to place breakpoints in the middle of instructions or on data within text segments, potentially causing crashes or unintended behavior. The fix requires CAP_SYS_ADMIN privilege for uprobes, affecting Linux systems where unprivileged users could previously use uprobes.

💻 Affected Systems

Products:

Linux kernel

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

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Affects systems where uprobes are enabled and unprivileged users can access them. The vulnerability exists in the kernel's uprobes implementation.

📦 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...

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 →

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 →

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 →

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

Unprivileged user could crash the kernel or cause system instability by placing uprobes in problematic locations, leading to denial of service.

🟠

Likely Case

Local unprivileged user could cause application crashes or kernel panics by misusing uprobes functionality.

🟢

If Mitigated

With CAP_SYS_ADMIN requirement, only privileged users can use uprobes, significantly reducing attack surface.

🌐 Internet-Facing: LOW - This is a local privilege vulnerability requiring local access to the system.

🏢 Internal Only: MEDIUM - Internal users with shell access could potentially exploit this to cause system instability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires local access and knowledge of how to misuse uprobes. No public exploits known at this time.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing commits: 183bdb89af1b5193b1d1d9316986053b15ca6fa4, 8e8bf7bc6aa6f583336c2fda280b6cea0aed5612, a0a8009083e569b5526c64f7d3f2a62baca95164, ba677dbe77af5ffe6204e0f3f547f3ba059c6302, c0aec35f861fa746ca45aa816161c74352e6ada8

Vendor Advisory: https://git.kernel.org/stable/c/183bdb89af1b5193b1d1d9316986053b15ca6fa4

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commits. 2. Reboot system to load new kernel. 3. Verify CAP_SYS_ADMIN is now required for uprobes.

🔧 Temporary Workarounds

Restrict uprobes access via capabilities

linux

Manually ensure only privileged users have CAP_SYS_ADMIN capability

# Remove CAP_SYS_ADMIN from unprivileged users
# Use setcap or capability bounding sets
# Example: sysctl -w kernel.cap-bound=... (system specific)

Disable uprobes via sysctl

linux

Disable uprobes functionality system-wide if not needed

# Check if uprobes is enabled
cat /sys/kernel/debug/tracing/uprobe_profile
# Disable via kernel boot parameter if supported

🧯 If You Can't Patch

Restrict shell access to trusted users only
Implement strict capability management to ensure only privileged users have CAP_SYS_ADMIN

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if uprobes can be used without CAP_SYS_ADMIN. Test with: 'perf probe -x /bin/ls' as non-root user.

Check Version:

uname -r

Verify Fix Applied:

Verify non-root users cannot create uprobes: 'perf probe -x /bin/ls' should fail with permission error. Check kernel version contains fix commits.

📡 Detection & Monitoring

Log Indicators:

Failed uprobes creation attempts by non-root users
Kernel oops or panic logs related to uprobes

Network Indicators:

None - local vulnerability only

SIEM Query:

Search for: 'uprobe' AND 'permission denied' OR 'capability' in system logs

📊 Metadata

CVE ID: CVE-2025-38466

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

EPSS Score: 0.02% exploit probability (4.4th percentile)

Published: July 25, 2025

Last Updated: December 22, 2025

🔗 References

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