CVE-2024-42270
📋 TL;DR
A race condition in the Linux kernel's netfilter iptables NAT module allows a null pointer dereference during system boot when iptables-restore is called before network namespace initialization completes. This vulnerability affects Linux systems using iptables NAT functionality and can cause kernel crashes. The issue occurs during a small time window at boot time when iptables-restore is executed.
💻 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 →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 panic leading to system crash and denial of service, requiring physical or remote console access to reboot the system.
Likely Case
System crash during boot when iptables-restore is executed, requiring manual intervention to restart the system.
If Mitigated
No impact if iptables-restore is not executed during the vulnerable boot window or if the system has been patched.
🎯 Exploit Status
Exploitation is difficult due to the narrow timing window and requirement for iptables-restore execution during boot. This appears to be a reliability issue rather than a security vulnerability for privilege escalation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commits 08ed888b69a22647153fe2bec55b7cd0a46102cc, 5830aa863981d43560748aa93589c0695191d95d, 70014b73d7539fcbb6b4ff5f37368d7241d8e626, 95590a4929027769af35b153645c0ab6fd22b29b, or b98ddb65fa1674b0e6b52de8af9103b63f51b643
Vendor Advisory: https://git.kernel.org/stable/c/08ed888b69a22647153fe2bec55b7cd0a46102cc
Restart Required: Yes
Instructions:
1. Update Linux kernel to a version containing the fix commits. 2. Check your distribution's security advisories for kernel updates. 3. Reboot the system after kernel update.
🔧 Temporary Workarounds
Delay iptables-restore execution
linuxModify boot scripts to delay iptables-restore execution until after system initialization completes
# Add sleep or dependency in systemd service or init script
# Example: Add 'sleep 5' before iptables-restore command
Disable iptables NAT if not needed
linuxRemove NAT rules or disable NAT functionality if not required for the system
# Check NAT rules: iptables -t nat -L
# Remove NAT rules if not needed
🧯 If You Can't Patch
- Ensure iptables-restore is not executed during early boot phase
- Monitor system logs for kernel panic indicators and have recovery procedures ready
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if it contains the vulnerable code by examining kernel commit history or checking with distribution vendorCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes one of the fix commits: 08ed888b69a22647153fe2bec55b7cd0a46102cc, 5830aa863981d43560748aa93589c0695191d95d, 70014b73d7539fcbb6b4ff5f37368d7241d8e626, 95590a4929027769af35b153645c0ab6fd22b29b, or b98ddb65fa1674b0e6b52de8af9103b63f51b643📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/messages or dmesg
- Null pointer dereference errors mentioning iptable_nat_table_init
- System crash during boot with iptables-restore in stack trace
Network Indicators:
- System becoming unresponsive during boot process
SIEM Query:
Search for kernel panic events or system crash reports during boot time with iptables-restore in process list🔗 References
- https://git.kernel.org/stable/c/08ed888b69a22647153fe2bec55b7cd0a46102cc
- https://git.kernel.org/stable/c/5830aa863981d43560748aa93589c0695191d95d
- https://git.kernel.org/stable/c/70014b73d7539fcbb6b4ff5f37368d7241d8e626
- https://git.kernel.org/stable/c/95590a4929027769af35b153645c0ab6fd22b29b
- https://git.kernel.org/stable/c/b98ddb65fa1674b0e6b52de8af9103b63f51b643
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
