CVE-2022-49498 – This CVE addresses a null pointer dereference v... (How to Fix)

Q: What is the severity of CVE-2022-49498?

CVE-2022-49498 has a CVSS score of 5.5 (MEDIUM). This CVE addresses a null pointer dereference vulnerability in the Linux kernel's ALSA PCM subsystem. If exploited, it could cause a kernel panic leading to denial of service. The vulnerability affects Linux systems with ALSA sound subsystem enabled.

📋 TL;DR

This CVE addresses a null pointer dereference vulnerability in the Linux kernel's ALSA PCM subsystem. If exploited, it could cause a kernel panic leading to denial of service. The vulnerability affects Linux systems with ALSA sound subsystem enabled.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific kernel versions containing the vulnerable code; exact range depends on distribution backports

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Requires ALSA sound subsystem to be enabled and used; most desktop and server Linux distributions include ALSA by default.

📦 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, potentially requiring physical or remote console access to reboot the system.

🟠

Likely Case

Local denial of service through kernel panic when specific ALSA operations are performed on malformed audio streams.

🟢

If Mitigated

Minimal impact as the vulnerability requires local access and specific conditions to trigger; systems with proper access controls would be largely unaffected.

🌐 Internet-Facing: LOW - This is a local privilege vulnerability requiring access to the audio subsystem, not directly exploitable over network.

🏢 Internal Only: MEDIUM - Local users or processes with audio device access could potentially crash the system, affecting availability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires local access and ability to interact with ALSA PCM subsystem; no known public exploits as of analysis.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions with the fix commits referenced in the CVE

Vendor Advisory: https://git.kernel.org/stable/c/011b559be832194f992f73d6c0d5485f5925a10b

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 ALSA sound subsystem

linux

Remove or blacklist ALSA kernel modules to prevent use of vulnerable code path

echo 'blacklist snd' >> /etc/modprobe.d/blacklist-alsa.conf
update-initramfs -u
reboot

🧯 If You Can't Patch

Restrict local user access to audio devices and ALSA interfaces
Implement strict access controls and monitor for unusual audio subsystem activity

🔍 How to Verify

Check if Vulnerable:

Check kernel version and compare with distribution's security advisories; examine if ALSA modules are loaded

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version after update matches patched version; check that system remains stable during audio operations

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in /var/log/kern.log or dmesg
ALSA subsystem error messages
System crash/reboot events

Network Indicators:

None - this is a local vulnerability

SIEM Query:

source="kernel" AND ("kernel panic" OR "BUG:" OR "null pointer dereference")

📊 Metadata

CVE ID: CVE-2022-49498

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-476

EPSS Score: 0.04% exploit probability (10.1th percentile)

Published: February 26, 2025

Last Updated: October 1, 2025

🔗 References

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