CVE-2021-37571 – This vulnerability in MediaTek Wi-Fi chipsets a... (How to Fix)

Q: What is the severity of CVE-2021-37571?

CVE-2021-37571 has a CVSS score of 8.2 (HIGH). This vulnerability in MediaTek Wi-Fi chipsets allows attackers to execute arbitrary code or cause denial of service through an out-of-bounds write in IEEE 1905 protocol handling. It affects NETGEAR and other devices using specific MediaTek chipsets. The vulnerability requires network proximity but can be exploited without authentication.

📋 TL;DR

This vulnerability in MediaTek Wi-Fi chipsets allows attackers to execute arbitrary code or cause denial of service through an out-of-bounds write in IEEE 1905 protocol handling. It affects NETGEAR and other devices using specific MediaTek chipsets. The vulnerability requires network proximity but can be exploited without authentication.

💻 Affected Systems

Products:

NETGEAR routers and access points with MediaTek chipsets
Other devices using affected MediaTek chipsets

Versions: Software versions up to and including 2.0.2

Operating Systems: Embedded Linux on affected networking devices

Default Config Vulnerable: ⚠️ Yes

Notes: Affects chipsets: MT7603E, MT7613, MT7615, MT7622, MT7628, MT7629, MT7915. IEEE 1905 protocol must be enabled (often default).

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete device compromise, persistent backdoor installation, and lateral movement within the network.

🟠

Likely Case

Denial of service causing Wi-Fi disruption, device crashes, or limited code execution for privilege escalation.

🟢

If Mitigated

Limited impact with proper network segmentation and firewall rules blocking IEEE 1905 protocol traffic.

🌐 Internet-Facing: MEDIUM - Requires network proximity but can be exploited from adjacent networks; many affected devices are consumer routers with internet-facing interfaces.

🏢 Internal Only: HIGH - Exploitable from any device on the same network segment, allowing lateral movement and privilege escalation.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires sending specially crafted IEEE 1905 protocol packets. No public exploit code available as of knowledge cutoff.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Versions after 2.0.2

Vendor Advisory: https://kb.netgear.com/000064368/Security-Advisory-for-WiFi-WPS-and-IEEE-1905-Vulnerabilities-on-Multiple-Products-PSV-2021-0298-PSV-2021-0300

Restart Required: Yes

Instructions:

1. Check device model and current firmware version. 2. Download latest firmware from NETGEAR support site. 3. Upload firmware via web interface. 4. Reboot device after update completes.

🔧 Temporary Workarounds

Disable IEEE 1905 protocol

all

Turn off IEEE 1905 (EasyMesh) functionality if not required

Check web interface for 'EasyMesh', '1905', or 'Multi-AP' settings and disable

Network segmentation

all

Isolate affected devices from untrusted networks

Configure VLANs to separate IoT/network devices from user networks
Implement firewall rules to block IEEE 1905 protocol traffic (port 1905/UDP)

🧯 If You Can't Patch

Replace affected devices with non-MediaTek alternatives or newer patched models
Implement strict network access controls and monitor for anomalous IEEE 1905 traffic

🔍 How to Verify

Check if Vulnerable:

Check device model against NETGEAR advisory list and verify firmware version is 2.0.2 or earlier

Check Version:

Check web interface under Advanced > Administration > Firmware Update or via SSH: cat /proc/version

Verify Fix Applied:

Confirm firmware version is updated beyond 2.0.2 and check that IEEE 1905 functionality works without crashes

📡 Detection & Monitoring

Log Indicators:

Kernel panic logs
Wi-Fi driver crashes
Repeated device reboots
IEEE 1905 protocol errors

Network Indicators:

Unusual IEEE 1905 protocol traffic patterns
Port 1905/UDP scans from untrusted sources
Malformed 1905 packets

SIEM Query:

source="router_logs" AND ("panic" OR "crash" OR "1905" OR "EasyMesh")

📊 Metadata

CVE ID: CVE-2021-37571

CVSS v3 Score: 8.2 (HIGH)

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

CWE: CWE-787

Published: December 26, 2021

Last Updated: November 21, 2024

🔗 References

https://corp.mediatek.com/product-security-bulletin/January-2022 Vendor Advisory
https://kb.netgear.com/000064368/Security-Advisory-for-WiFi-WPS-and-IEEE-1905-Vulnerabilities-on-Multiple-Products-PSV-2021-0298-PSV-2021-0300 Third Party Advisory
https://corp.mediatek.com/product-security-bulletin/January-2022 Vendor Advisory
https://kb.netgear.com/000064368/Security-Advisory-for-WiFi-WPS-and-IEEE-1905-Vulnerabilities-on-Multiple-Products-PSV-2021-0298-PSV-2021-0300 Third Party Advisory

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