CVE-2020-37092: Netis E1+ Auth Bypass Vulnerability

CVE-2020-37092 Overview

CVE-2020-37092 is a hardcoded credentials vulnerability affecting the Netis E1+ network device running firmware version 1.2.32533. The device contains an embedded root account with a crackable password, allowing unauthenticated attackers to gain full administrative access over the network. This vulnerability falls under CWE-798 (Use of Hard-coded Credentials) and represents a severe security flaw commonly found in consumer-grade networking equipment.

Critical Impact

Unauthenticated attackers can leverage hardcoded root credentials to gain complete administrative control over the Netis E1+ device, potentially compromising the entire network segment.

Affected Products

• Netis E1+ firmware version 1.2.32533

Discovery Timeline

• 2026-02-03 - CVE CVE-2020-37092 published to NVD
• 2026-02-04 - Last updated in NVD database

Technical Details for CVE-2020-37092

Vulnerability Analysis

This vulnerability exists due to the presence of hardcoded root credentials embedded within the Netis E1+ firmware. The device ships with a predefined root account that uses a weak, crackable password. Because these credentials are built directly into the firmware, they cannot be changed by end users and remain consistent across all affected devices.

The attack is network-accessible with low complexity, requiring no prior authentication or user interaction. An attacker who discovers these credentials can authenticate to the device and gain full administrative privileges, enabling complete control over the router's configuration, traffic routing, and connected network segments.

Root Cause

The root cause is the inclusion of hardcoded credentials within the device firmware (CWE-798). This insecure development practice embeds static authentication credentials that are identical across all deployed units of the affected product. The weak password associated with the root account can be cracked using common password cracking tools, making exploitation trivial once the credential scheme is discovered.

Attack Vector

The attack vector is network-based, allowing remote exploitation without any user interaction. An attacker can:

1. Identify Netis E1+ devices on the network through service fingerprinting or banner grabbing
2. Attempt authentication using the known hardcoded root credentials
3. Upon successful authentication, gain full administrative access to the device
4. Modify device configurations, intercept traffic, pivot to internal network resources, or deploy persistent backdoors

Technical details regarding the specific exploitation methodology are available through the Exploit-DB #48382 and the VulnCheck Netis Advisory.

Detection Methods for CVE-2020-37092

Indicators of Compromise

• Unexpected authentication attempts or successful logins to the root account on Netis E1+ devices
• Configuration changes on network devices that were not authorized by administrators
• Unusual outbound connections or traffic patterns originating from the router
• Evidence of firmware modifications or unauthorized administrative sessions

Detection Strategies

• Monitor authentication logs on network devices for root account login attempts from unexpected source IP addresses
• Implement network intrusion detection rules to alert on authentication traffic to Netis E1+ management interfaces
• Conduct periodic firmware integrity checks to identify unauthorized modifications
• Deploy honeypot Netis devices to detect credential exploitation attempts in your environment

Monitoring Recommendations

• Enable verbose logging on all network infrastructure devices and forward logs to a centralized SIEM platform
• Configure alerts for any successful root-level authentication events on Netis E1+ devices
• Perform regular network scans to identify exposed Netis E1+ management interfaces
• Review network device configurations periodically for unauthorized changes

How to Mitigate CVE-2020-37092

Immediate Actions Required

• Isolate affected Netis E1+ devices from untrusted network segments immediately
• Restrict management interface access to trusted administrative IP addresses using firewall rules
• Disable remote management interfaces if not required for operations
• Consider replacing vulnerable devices with products from vendors that follow secure development practices

Patch Information

No vendor patch information is currently available for this vulnerability. Users should contact Netis Systems directly for firmware update availability. Given the nature of hardcoded credential vulnerabilities, a firmware update from the vendor would be required to remediate this issue.

Workarounds

• Implement network segmentation to isolate affected devices from sensitive network resources
• Deploy access control lists (ACLs) or firewall rules to restrict management interface access to specific trusted IP addresses
• Monitor all traffic to and from affected devices for anomalous activity
• Consider device replacement if vendor does not provide a timely security patch

# Example firewall rule to restrict management access (iptables)
# Replace 192.168.1.100 with your Netis E1+ device IP
# Replace 10.0.0.5 with your trusted admin workstation IP

iptables -A INPUT -d 192.168.1.100 -p tcp --dport 80 -s 10.0.0.5 -j ACCEPT
iptables -A INPUT -d 192.168.1.100 -p tcp --dport 23 -s 10.0.0.5 -j ACCEPT
iptables -A INPUT -d 192.168.1.100 -p tcp --dport 80 -j DROP
iptables -A INPUT -d 192.168.1.100 -p tcp --dport 23 -j DROP