CVE-2025-21741
📋 TL;DR
This CVE describes an out-of-bounds read vulnerability in the Linux kernel's ipheth USB network driver. An attacker could exploit this to read kernel memory, potentially leading to information disclosure or system crashes. Systems using affected Linux kernel versions with ipheth driver enabled are vulnerable.
💻 Affected Systems
- Linux kernel
📦 What is this software?
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
Kernel memory disclosure leading to privilege escalation or system compromise through additional vulnerabilities
Likely Case
System crash (kernel panic) or information disclosure from kernel memory
If Mitigated
Limited impact due to kernel protections like KASLR, with potential for denial of service
🎯 Exploit Status
Requires local access and ability to connect a malicious USB device or manipulate USB traffic
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Multiple stable kernel versions with commits: 22475242ddb70e35c9148234be9a3aa9fb8efff9, 5835bf66c50ac2b85ed28b282c2456c3516ef0a6, 971b8c572559e52d32a2b82f2d9e0685439a0117, ee591f2b281721171896117f9946fced31441418
Vendor Advisory: https://git.kernel.org/stable/c/22475242ddb70e35c9148234be9a3aa9fb8efff9
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable ipheth module
LinuxPrevent loading of vulnerable ipheth driver
echo 'blacklist ipheth' >> /etc/modprobe.d/blacklist-ipheth.conf
rmmod ipheth
🧯 If You Can't Patch
- Restrict physical USB access to trusted devices only
- Disable USB tethering functionality if not required
🔍 How to Verify
Check if Vulnerable:
Check if ipheth module is loaded: lsmod | grep iphethCheck Version:
uname -rVerify Fix Applied:
Check kernel version after update and verify ipheth module version if loaded📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- System crashes related to ipheth driver
- USB device connection errors
Network Indicators:
- Unusual USB device enumeration patterns
- Unexpected USB network interface creation
SIEM Query:
source="kernel" AND ("ipheth" OR "USB network" OR "DPE") AND ("panic" OR "oops" OR "segfault")