CVE-2026-24440: Tenda W30e Auth Bypass Vulnerability

CVE-2026-24440 Overview

CVE-2026-24440 is a broken access control vulnerability affecting Shenzhen Tenda W30E V2 firmware versions up to and including V16.01.0.19(5037). The vulnerability allows account passwords to be changed through the maintenance interface without requiring verification of the existing password. This enables unauthorized password changes when access to the affected endpoint is obtained, potentially leading to complete device takeover.

Critical Impact
Attackers with network access to the device's maintenance interface can change administrator credentials without knowing the current password, enabling full device compromise and potential network intrusion.

Affected Products

Tenda W30E Firmware versions up to and including V16.01.0.19(5037)
Tenda W30E Hardware Version 2.0
Tenda W30E V2 Enterprise Wireless Router

Discovery Timeline

2026-01-26 - CVE-2026-24440 published to NVD
2026-01-28 - Last updated in NVD database

Technical Details for CVE-2026-24440

Vulnerability Analysis

This vulnerability is classified under CWE-620 (Unverified Password Change), which occurs when a password change mechanism does not require knowledge of the original password before permitting the password to be changed. In the context of the Tenda W30E V2, the maintenance interface exposes functionality that allows authenticated or partially-authenticated users to modify account credentials without the standard security verification step of confirming the existing password.

The flaw represents a fundamental authentication design weakness in the device's web management interface. When exploited, this vulnerability can be leveraged for privilege escalation, enabling attackers to lock out legitimate administrators and gain persistent unauthorized access to the network device.

Root Cause

The root cause stems from improper implementation of the password change functionality within the Tenda W30E V2 firmware's maintenance interface. The firmware fails to implement proper authentication controls that would verify the user's knowledge of the current password before allowing credential modifications. This design flaw violates the principle of defense in depth and standard secure password change practices.

Attack Vector

The attack is network-based and can be executed by any user who gains access to the device's maintenance interface. The exploitation path involves:

An attacker gains network access to the Tenda W30E V2 device (either through the local network or if the management interface is exposed to the internet)
The attacker navigates to the password change functionality in the maintenance interface
Without needing to supply the current administrative password, the attacker submits a new password
The device accepts the password change request, granting the attacker full administrative control

The vulnerability does not require user interaction and can be exploited with low privileges, making it particularly dangerous in enterprise environments where these devices are deployed. For detailed technical information, refer to the VulnCheck Security Advisory.

Detection Methods for CVE-2026-24440

Indicators of Compromise

Unexpected administrative password changes on Tenda W30E V2 devices
Unauthorized configuration modifications or device settings changes
Unusual network traffic to the device's management interface from unexpected IP addresses
Login failures for legitimate administrators followed by successful access from unknown sources

Detection Strategies

Monitor authentication logs on network infrastructure for password change events without corresponding verification attempts
Implement network traffic analysis to detect requests to the password change endpoint from unauthorized sources
Deploy intrusion detection signatures that identify exploitation attempts targeting the maintenance interface
Audit device configurations regularly to detect unauthorized changes to administrative credentials

Monitoring Recommendations

Enable logging on all Tenda W30E V2 devices and forward logs to a centralized SIEM for correlation
Set up alerts for any password modification events on network infrastructure devices
Monitor for unusual access patterns to device management interfaces, particularly from external IP addresses
Implement baseline monitoring to detect deviations in device configuration states

How to Mitigate CVE-2026-24440

Immediate Actions Required

Restrict network access to the Tenda W30E V2 management interface to trusted administrative networks only
Implement firewall rules to block external access to the device's web management interface
Consider disabling the web management interface entirely if not required and use alternative management methods
Monitor for any unauthorized configuration changes and reset credentials if compromise is suspected
Evaluate replacing affected devices with alternatives that implement proper authentication controls

Patch Information

At the time of publication, no vendor patch has been released for this vulnerability. Organizations should consult the Tenda W30E Product Page for firmware updates and monitor for security advisories from Tenda. Given the severity of this authentication bypass vulnerability, organizations should implement compensating controls until a patch becomes available.

Workarounds

Isolate affected Tenda W30E V2 devices on a separate VLAN with strict access controls
Implement network-level authentication (such as 802.1X) to restrict which devices can communicate with the management interface
Use a VPN or jump host architecture to access device management interfaces rather than direct network exposure
Deploy network access control lists (ACLs) to limit management interface access to specific administrator IP addresses

bash

# Example firewall rule to restrict management interface access (iptables)
# Allow management access only from trusted admin network 192.168.10.0/24
iptables -A INPUT -p tcp --dport 80 -s 192.168.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 192.168.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP