CVE-2022-48911

Q: What is the severity of CVE-2022-48911?

CVE-2022-48911 has a CVSS score of 5.5 (MEDIUM). This is a use-after-free vulnerability in the Linux kernel's netfilter nf_queue component. It allows attackers to potentially crash the kernel or execute arbitrary code by exploiting improper reference counting when queuing packets fails. Systems running vulnerable Linux kernel versions with netfilter enabled are affected.

5.5 MEDIUM

Denial of Service

📋 TL;DR

This is a use-after-free vulnerability in the Linux kernel's netfilter nf_queue component. It allows attackers to potentially crash the kernel or execute arbitrary code by exploiting improper reference counting when queuing packets fails. Systems running vulnerable Linux kernel versions with netfilter enabled are affected.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific vulnerable versions include those referenced in the git commits (21b27b2baa27423286e9b8d3f0b194d587083d95, 34dc4a6a7f261736ef7183868a5bddad31c7f9e3, 43c25da41e3091b31a906651a43e80a2719aa1ff, 4d05239203fa38ea8a6f31e228460da4cb17a71a, c3873070247d9e3c7a6b0cf9bf9b45e8018427b1) and related kernel versions with the vulnerable code.

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Requires netfilter subsystem to be enabled and configured to use nf_queue. Not all Linux systems use this specific netfilter component.

📦 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...

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⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash or potential arbitrary code execution with kernel privileges, resulting in complete system compromise.

🟠

Likely Case

Kernel crash causing denial of service, requiring system reboot to restore functionality.

🟢

If Mitigated

Minimal impact if proper network segmentation and least privilege principles are followed, with crashes contained to affected systems.

🌐 Internet-Facing: MEDIUM - Exploitation requires network packet processing but depends on specific netfilter configurations and attacker ability to trigger the failure condition.

🏢 Internal Only: MEDIUM - Internal attackers with network access could potentially trigger the vulnerability if they can send specially crafted packets to vulnerable systems.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: HIGH

Exploitation requires triggering specific failure conditions in packet queuing and manipulating socket reference counts. No public exploit code has been identified.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing the fixes referenced in the git commits

Vendor Advisory: https://git.kernel.org/stable/c/21b27b2baa27423286e9b8d3f0b194d587083d95

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.

🔧 Temporary Workarounds

Disable nf_queue if not needed

linux

If nf_queue functionality is not required for your use case, disable it to remove the attack surface.

Check if nf_queue is in use: lsmod | grep nf_queue
Unload module if possible: sudo rmmod nf_queue

Network filtering

linux

Implement network controls to limit who can send packets to systems using nf_queue.

Use iptables/nftables to restrict access: sudo iptables -A INPUT -p tcp --dport [your-ports] -j DROP

🧯 If You Can't Patch

Implement strict network segmentation to isolate systems using nf_queue
Apply principle of least privilege and monitor systems for crash events

🔍 How to Verify

Check if Vulnerable:

Check kernel version and compare with patched versions from your distribution. Examine if nf_queue module is loaded: lsmod | grep nf_queue

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version after update matches patched version. Check system logs for any crash events related to netfilter.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in /var/log/messages or dmesg
System crash/reboot events
Netfilter/nf_queue related error messages

Network Indicators:

Unusual packet patterns targeting systems with netfilter enabled
Multiple connection attempts to trigger queuing failures

SIEM Query:

source="kernel" AND ("panic" OR "Oops" OR "netfilter" OR "nf_queue")

📊 Metadata

CVE ID: CVE-2022-48911

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

CWE: CWE-416

Published: August 22, 2024

Last Updated: September 12, 2024

📋 TL;DR

💻 Affected Systems

📦 What is this software?

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 nf_queue if not needed

Network filtering

🧯 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