CVE-2025-46634 Overview
CVE-2025-46634 affects the web management portal of the Tenda RX2 Pro router running firmware version 16.03.30.14. The portal transmits the user's password hash in cleartext before encryption is established. An unauthenticated attacker on the network path can capture the hash from observed traffic and replay it to authenticate. The flaw is classified as cleartext transmission of sensitive information [CWE-312] and stems from a flawed authentication sequence in the embedded httpd service.
Critical Impact
Network-positioned attackers can capture and replay password hashes to gain administrative access to the router web interface without credentials.
Affected Products
- Tenda RX2 Pro router (hardware)
- Tenda RX2 Pro firmware version 16.03.30.14
- Tenda RX2 Pro web management portal (httpd)
Discovery Timeline
- 2025-05-01 - CVE-2025-46634 published to NVD
- 2025-05-27 - Last updated in NVD database
Technical Details for CVE-2025-46634
Vulnerability Analysis
The Tenda RX2 Pro web management portal implements an authentication flow that encrypts session traffic only after the client has already submitted the password hash. The browser computes a hash of the user password and sends it to the device httpd service over an unencrypted channel during the initial login exchange. Encryption is negotiated afterward, leaving the credential material exposed during the most sensitive step of the handshake.
Because the server accepts the hash itself as the authentication token, an attacker does not need to recover the plaintext password. Capturing the hash on the wire is sufficient to authenticate as the legitimate user. This collapses the protection that hashing would otherwise provide and converts a credential confidentiality issue into a full authentication bypass.
Root Cause
The root cause is an ordering defect in the authentication protocol. The portal performs hash-based authentication before establishing a confidential transport. The hash also functions as a bearer token, so any party that observes it can reuse it. The implementation conflates password obfuscation with replay protection.
Attack Vector
An attacker on the same local network, on an upstream segment, or in a position to perform passive interception captures the HTTP login request to the router. The request contains the password hash. The attacker then submits the captured hash in a new authentication request to the portal and gains administrator access to the device.
The vulnerability does not require user interaction beyond a legitimate administrator logging in while the attacker is observing. No code execution primitive is needed to exploit it. Refer to the Uturn Blog CVE-2025-46634 Analysis for the protocol-level walkthrough.
Detection Methods for CVE-2025-46634
Indicators of Compromise
- Unexpected administrator logins to the Tenda RX2 Pro portal from LAN hosts that do not belong to network administrators.
- Duplicate authentication requests carrying identical password hash values from different source IP addresses within a short window.
- Configuration changes on the router (DNS, port forwarding, firmware) that do not correlate with sanctioned change windows.
Detection Strategies
- Inspect HTTP traffic to the router management interface for login requests containing hashed credentials transmitted without TLS.
- Correlate router admin session events with the source MAC and IP of known administrator workstations to flag anomalous origins.
- Monitor for ARP spoofing or rogue DHCP activity on segments that reach the router management VLAN, since these enable on-path capture.
Monitoring Recommendations
- Forward router syslog and authentication events to a centralized SIEM such as Singularity Data Lake for retention and correlation.
- Alert on configuration export, firmware change, and account creation actions on the device.
- Track endpoint network telemetry from administrator workstations to identify unauthorized scanning or credential replay tooling on the LAN.
How to Mitigate CVE-2025-46634
Immediate Actions Required
- Restrict access to the router web management portal to a dedicated management VLAN or single administrative host.
- Disable remote (WAN-side) management on the Tenda RX2 Pro until a fixed firmware is installed.
- Rotate the administrator password and any reused credentials after assuming the hash may have been observed.
Patch Information
No vendor patch is referenced in the NVD entry at the time of publication. Check the Tenda Official Website for firmware updates superseding 16.03.30.14 and apply them once available.
Workarounds
- Administer the device only over a wired connection from a trusted host to reduce exposure of the login exchange.
- Segment IoT and network infrastructure away from user endpoints so that a compromised client cannot sniff router management traffic.
- Place the management interface behind a VPN or jump host that enforces TLS and mutual authentication.
# Example: restrict router management access to a single admin host using an upstream firewall
iptables -A FORWARD -d 192.0.2.1 -p tcp --dport 80 -s 192.0.2.50 -j ACCEPT
iptables -A FORWARD -d 192.0.2.1 -p tcp --dport 80 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
