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CVE-2020-26919

9.8 CRITICAL
Authentication Bypass

📋 TL;DR

This vulnerability in NETGEAR JGS516PE switches allows attackers to bypass access controls and execute administrative functions without authentication. It affects all JGS516PE devices running firmware versions before 2.6.0.43. Attackers can potentially take full control of the network switch.

💻 Affected Systems

Products:
  • NETGEAR JGS516PE
Versions: All versions before 2.6.0.43
Operating Systems: Embedded switch firmware
Default Config Vulnerable: ⚠️ Yes
Notes: All JGS516PE switches with default configurations are vulnerable. The vulnerability exists in the web management interface.

📦 What is this software?

Jgs516pe Firmware by Netgear

View all CVEs affecting Jgs516pe Firmware →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete compromise of the network switch allowing attackers to reconfigure network settings, intercept traffic, disable network segments, or use the device as a pivot point for further attacks.

🟠

Likely Case

Unauthorized configuration changes to the switch, including VLAN manipulation, port configuration changes, or disabling network connectivity for connected devices.

🟢

If Mitigated

Limited impact if proper network segmentation and access controls prevent external access to the switch management interface.

🌐 Internet-Facing: HIGH - If the management interface is exposed to the internet, attackers can remotely exploit this without authentication.
🏢 Internal Only: HIGH - Even internally, any user with network access to the switch management interface can exploit this vulnerability.

🎯 Exploit Status

Public PoC: ✅ No
Weaponized: LIKELY
Unauthenticated Exploit: ⚠️ Yes
Complexity: LOW

The vulnerability allows unauthenticated access to administrative functions. While no public PoC exists, the nature of the vulnerability makes exploitation straightforward for attackers with network access to the management interface.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 2.6.0.43

Vendor Advisory: https://kb.netgear.com/000062334/Security-Advisory-for-Missing-Function-Level-Access-Control-on-JGS516PE-PSV-2020-0377

Restart Required: Yes

Instructions:

1. Download firmware version 2.6.0.43 from NETGEAR support site. 2. Log into the switch web interface. 3. Navigate to Maintenance > Firmware Upgrade. 4. Upload and install the new firmware. 5. The switch will reboot automatically.

🔧 Temporary Workarounds

Restrict Management Interface Access

all

Limit access to the switch management interface to trusted IP addresses only using ACLs or firewall rules.

Disable Web Management Interface

all

If CLI access is sufficient, disable the vulnerable web management interface entirely.

configure terminal
no ip http server
end
write memory

🧯 If You Can't Patch

  • Isolate the switch on a dedicated management VLAN with strict access controls
  • Implement network monitoring for unauthorized configuration changes to the switch

🔍 How to Verify

Check if Vulnerable:

Check the firmware version in the switch web interface under Maintenance > Firmware or via CLI using 'show version' command.

Check Version:

show version

Verify Fix Applied:

Verify the firmware version is 2.6.0.43 or later in the web interface or via CLI.

📡 Detection & Monitoring

Log Indicators:

  • Unauthorized access attempts to administrative URLs
  • Configuration changes from unexpected IP addresses
  • Multiple failed login attempts followed by successful administrative actions

Network Indicators:

  • HTTP requests to administrative endpoints without prior authentication
  • Traffic to switch management interface from unexpected sources

SIEM Query:

source_ip=* AND (url_path CONTAINS "/admin/" OR url_path CONTAINS "/config/") AND http_status=200 AND NOT user_agent CONTAINS "expected_admin_user_agent"

📊 Metadata

CVE ID: CVE-2020-26919
CVSS v3 Score: 9.8 (CRITICAL)
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: October 9, 2020
Last Updated: November 7, 2025

🔗 References

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