CVE-2022-49571 – This CVE describes a race condition vulnerabili... (How to Fix)

Q: What is the severity of CVE-2022-49571?

CVE-2022-49571 has a CVSS score of 4.7 (MEDIUM). This CVE describes a race condition vulnerability in the Linux kernel's TCP implementation where concurrent reading and writing of the sysctl_tcp_max_reordering variable can cause data races. This affects Linux systems using the vulnerable kernel versions. Attackers could potentially exploit this to cause denial of service or other undefined behavior.

📋 TL;DR

This CVE describes a race condition vulnerability in the Linux kernel's TCP implementation where concurrent reading and writing of the sysctl_tcp_max_reordering variable can cause data races. This affects Linux systems using the vulnerable kernel versions. Attackers could potentially exploit this to cause denial of service or other undefined behavior.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific vulnerable kernel versions referenced in the git commits (need to check exact ranges from provided links)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems where TCP connections are actively used and sysctl_tcp_max_reordering is being modified concurrently.

📦 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 →

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 →

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 or system crash leading to denial of service, potentially allowing attackers to disrupt critical network services.

🟠

Likely Case

Minor performance degradation or occasional TCP connection issues due to inconsistent reordering values being used.

🟢

If Mitigated

No impact if proper kernel patches are applied or if the system isn't under heavy concurrent TCP load.

🌐 Internet-Facing: LOW - Requires local access or ability to manipulate kernel parameters; not directly exploitable over network.

🏢 Internal Only: LOW - Requires local access to modify sysctl parameters; privilege escalation needed for meaningful impact.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: HIGH

Race conditions are difficult to reliably exploit; requires precise timing and local access to trigger.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing the referenced git commits (064852663308c801861bd54789d81421fa4c2928 and others)

Vendor Advisory: https://git.kernel.org/stable/c/064852663308c801861bd54789d81421fa4c2928

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable concurrent sysctl modifications

linux

Prevent concurrent access to sysctl_tcp_max_reordering parameter

echo 1 > /proc/sys/vm/drop_caches
sysctl -w kernel.sysctl_writes_strict=1

🧯 If You Can't Patch

Restrict access to sysctl interface to privileged users only
Monitor system logs for kernel panic or TCP connection anomalies

🔍 How to Verify

Check if Vulnerable:

Check kernel version against affected ranges: uname -r and compare with distribution security advisories

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version after update matches patched versions from git commits

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
TCP connection resets or timeouts in system logs

Network Indicators:

Unusual TCP retransmission patterns
Connection instability

SIEM Query:

source="kernel" AND ("panic" OR "Oops" OR "TCP" AND "reset")

📊 Metadata

CVE ID: CVE-2022-49571

CVSS v3 Score: 4.7 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-362

EPSS Score: 0.03% exploit probability (7.2th percentile)

Published: February 26, 2025

Last Updated: October 1, 2025

🔗 References

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🔗 Related Vulnerabilities

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