CVE-2025-46632 Overview
CVE-2025-46632 is a cryptographic weakness affecting the Tenda RX2 Pro router running firmware version 16.03.30.14. The httpd component of the web management portal reuses a static initialization vector (IV) when encrypting messages between the client and the server. An attacker on the network can leverage this IV reuse to infer information about encrypted traffic or accelerate decryption of intercepted messages. The issue is categorized under CWE-323: Reusing a Nonce, Key Pair in Encryption.
Critical Impact
An attacker positioned to observe traffic to the router's management interface can weaken confidentiality of administrative sessions and potentially recover plaintext material from encrypted messages.
Affected Products
- Tenda RX2 Pro (hardware)
- Tenda RX2 Pro Firmware version 16.03.30.14
- Web management portal httpd component
Discovery Timeline
- 2025-05-01 - CVE-2025-46632 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-46632
Vulnerability Analysis
The Tenda RX2 Pro web management portal encrypts messages exchanged between the browser client and the router's httpd service. The implementation uses a fixed initialization vector rather than generating a fresh, unpredictable IV per message. Because the IV is static across sessions and messages, ciphertexts produced with the same key leak structural information about the underlying plaintext.
For block ciphers operating in modes such as CBC, IV reuse allows an attacker to detect when identical plaintext blocks are encrypted. In stream-cipher-like modes, IV reuse under the same key can enable direct plaintext recovery through XOR of two ciphertexts. Either scenario undermines the confidentiality guarantee that the encryption layer is meant to provide for administrative traffic.
Root Cause
The root cause is a design flaw in the cryptographic routines used by the httpd binary on the router. The IV value is hardcoded or otherwise reused across encryption operations instead of being freshly generated per message. This violates the requirement that IVs be unique for every encryption performed under the same key.
Attack Vector
The vulnerability is exploitable over the network without authentication or user interaction. An attacker able to observe or capture traffic to the router's web management portal can collect multiple ciphertext samples produced under the same key and static IV. By comparing these samples, the attacker can infer information about the encrypted content or accelerate cryptanalytic decryption. Full technical analysis is available in the Uturn Blog CVE-2025-46632 Writeup.
No public exploit code or proof-of-concept payload has been published in Exploit-DB or CISA KEV at the time of writing. No synthetic exploitation code is provided here because no verified sample exists.
Detection Methods for CVE-2025-46632
Indicators of Compromise
- Repeated ciphertext patterns in captured HTTPS or custom-encrypted payloads to the router's management interface.
- Unexpected network captures targeting TCP traffic to the Tenda RX2 Pro management port from untrusted hosts.
- Unusual sniffing activity on network segments where the router's admin interface is reachable.
Detection Strategies
- Inspect firmware version strings reported by the router and flag any device running 16.03.30.14 as vulnerable.
- Monitor for passive traffic capture tools on network segments that host Tenda RX2 Pro devices.
- Correlate repeated administrative logins from unusual client addresses with concurrent packet-capture indicators.
Monitoring Recommendations
- Log and alert on access to the router's web management portal from outside a defined administrative subnet.
- Track failed and successful authentication attempts against the httpd interface to identify session replay or brute-force behavior.
- Baseline normal management traffic volume and flag deviations that could indicate large-scale ciphertext collection.
How to Mitigate CVE-2025-46632
Immediate Actions Required
- Restrict access to the router's web management portal to a trusted management VLAN or specific IP addresses.
- Disable remote (WAN-side) administration on the Tenda RX2 Pro until a firmware update is available.
- Rotate any administrative credentials that may have been transmitted over the vulnerable encrypted channel.
- Check the Tenda Official Website for firmware updates addressing the httpd IV reuse.
Patch Information
At the time of the last NVD update on 2026-06-17, no vendor advisory URL or fixed firmware version is listed in the CVE record. Administrators should monitor the Tenda Official Website for a firmware release that supersedes 16.03.30.14 and explicitly addresses CWE-323.
Workarounds
- Place the router's management interface behind a VPN and disallow direct network exposure to untrusted clients.
- Segment the management network so packet capture by unauthorized hosts is not feasible.
- Perform administrative tasks only from a dedicated, wired management workstation to reduce the opportunity for traffic interception.
# Example: restrict router management access with an upstream firewall rule
# Allow only the admin workstation 192.0.2.10 to reach the router at 192.0.2.1
iptables -A FORWARD -s 192.0.2.10 -d 192.0.2.1 -p tcp --dport 443 -j ACCEPT
iptables -A FORWARD -d 192.0.2.1 -p tcp --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
