CVE-2024-49938 – This vulnerability in the Linux kernel's ath9k

Q: What is the severity of CVE-2024-49938?

CVE-2024-49938 has a CVSS score of 5.5 (MEDIUM). This vulnerability in the Linux kernel's ath9k_htc WiFi driver involves improper handling of USB urb resubmission with uninitialized skb length values. It could lead to kernel memory corruption or system crashes when specific error conditions occur during WiFi operations. Systems using affected ath9k_htc WiFi hardware with vulnerable kernel versions are at risk.

📋 TL;DR

This vulnerability in the Linux kernel's ath9k_htc WiFi driver involves improper handling of USB urb resubmission with uninitialized skb length values. It could lead to kernel memory corruption or system crashes when specific error conditions occur during WiFi operations. Systems using affected ath9k_htc WiFi hardware with vulnerable kernel versions are at risk.

💻 Affected Systems

Products:

Linux kernel with ath9k_htc driver

Versions: Kernel versions containing vulnerable ath9k_htc driver code before the fix commits

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems using ath9k_htc WiFi hardware (Atheros USB WiFi adapters). Requires specific error conditions during USB urb handling.

📦 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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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

Kernel memory corruption leading to system crash, denial of service, or potential privilege escalation if combined with other vulnerabilities.

🟠

Likely Case

System instability or kernel panic when WiFi operations encounter specific error conditions, resulting in denial of service.

🟢

If Mitigated

No impact if patched or if error conditions don't trigger the vulnerable code path.

🌐 Internet-Facing: LOW - Requires local WiFi hardware access and specific error conditions.

🏢 Internal Only: MEDIUM - Internal systems with vulnerable WiFi hardware could experience instability during network operations.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: HIGH

Exploitation requires triggering specific error paths in USB callback functions and may only lead to denial of service rather than code execution.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing commits 012ae530afa0785102360de452745d33c99a321b and related fixes

Vendor Advisory: https://git.kernel.org/stable/c/012ae530afa0785102360de452745d33c99a321b

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager to update kernel package. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable ath9k_htc driver

linux

Prevent loading of vulnerable driver module

echo 'blacklist ath9k_htc' >> /etc/modprobe.d/blacklist-ath9k.conf
rmmod ath9k_htc

Use alternative WiFi hardware

all

Replace Atheros USB WiFi adapters with unaffected hardware

🧯 If You Can't Patch

Disconnect or disable vulnerable WiFi hardware
Implement network segmentation to isolate systems with vulnerable hardware

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if ath9k_htc module is loaded: 'uname -r' and 'lsmod | grep ath9k_htc'

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is updated and check driver version in dmesg: 'dmesg | grep ath9k_htc'

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
ath9k_htc driver error messages in dmesg
USB urb resubmission failures

Network Indicators:

WiFi connectivity drops on affected hardware
Unusual USB error rates

SIEM Query:

source="kernel" AND ("ath9k_htc" OR "USB urb") AND ("panic" OR "error" OR "resubmit")

📊 Metadata

CVE ID: CVE-2024-49938

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-824

Published: October 21, 2024

Last Updated: November 3, 2025

🔗 References

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🔗 Related Vulnerabilities

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