CVE-2026-3271: Tenda F453 Firmware Buffer Overflow Flaw

CVE-2026-3271 Overview

A critical buffer overflow vulnerability has been identified in the Tenda F453 wireless router firmware version 1.0.0.3. This vulnerability affects the fromP2pListFilter function within the /goform/P2pListFilterof endpoint of the httpd web server component. Improper handling of the page argument allows an authenticated attacker to trigger a buffer overflow condition, potentially leading to remote code execution or denial of service.

Critical Impact

Remote authenticated attackers can exploit this buffer overflow to potentially execute arbitrary code or crash the device, compromising network security and availability.

Affected Products

• Tenda F453 Firmware version 1.0.0.3
• Tenda F453 Hardware Device

Discovery Timeline

• 2026-02-27 - CVE-2026-3271 published to NVD
• 2026-02-27 - Last updated in NVD database

Technical Details for CVE-2026-3271

Vulnerability Analysis

This vulnerability stems from improper buffer boundary checking in the fromP2pListFilter function of the Tenda F453 router's web management interface. When processing HTTP requests to the /goform/P2pListFilterof endpoint, the function fails to properly validate the length of user-supplied input in the page parameter before copying it into a fixed-size buffer.

The vulnerability is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-120 (Buffer Copy without Checking Size of Input), indicating a classic buffer overflow condition where input data exceeds the allocated buffer capacity.

Root Cause

The root cause lies in the absence of proper input validation and boundary checking in the fromP2pListFilter function. When the page argument is processed, the function copies the user-supplied data into a stack or heap buffer without verifying that the input length does not exceed the buffer's allocated size. This allows an attacker to provide an oversized input that overwrites adjacent memory regions.

Attack Vector

The attack can be launched remotely over the network by any authenticated user with access to the router's web management interface. An attacker would craft a malicious HTTP request to the /goform/P2pListFilterof endpoint with an oversized page parameter value. When the vulnerable function processes this request, the buffer overflow occurs, potentially allowing the attacker to:

1. Overwrite return addresses to hijack control flow
2. Corrupt critical data structures in memory
3. Cause a denial of service by crashing the httpd process
4. Potentially achieve remote code execution with router privileges

The exploit for this vulnerability has been publicly disclosed, increasing the risk of active exploitation. Technical details are available in the GitHub Vulnerability Repository.

Detection Methods for CVE-2026-3271

Indicators of Compromise

• Unusual HTTP POST requests to /goform/P2pListFilterof with abnormally long page parameter values
• Unexpected crashes or restarts of the httpd service on Tenda F453 devices
• Memory corruption signatures in router logs if logging is enabled
• Anomalous outbound network traffic from the router following exploitation attempts

Detection Strategies

• Implement network intrusion detection rules to monitor for oversized HTTP parameters targeting Tenda router management endpoints
• Deploy web application firewall (WAF) rules to block requests with excessively long parameter values to /goform/ endpoints
• Monitor for HTTP requests containing buffer overflow payloads or NOP sled patterns targeting the affected endpoint
• Utilize SentinelOne Singularity to detect anomalous process behavior and memory corruption attempts on network infrastructure

Monitoring Recommendations

• Enable verbose logging on Tenda F453 devices to capture web management interface access attempts
• Implement network segmentation to limit exposure of router management interfaces
• Configure alerts for repeated authentication attempts or unusual request patterns to the device
• Regularly review VulDB CTI ID #347995 for updated threat intelligence

How to Mitigate CVE-2026-3271

Immediate Actions Required

• Restrict access to the router's web management interface to trusted IP addresses only
• Disable remote management access if not required for operations
• Implement network segmentation to isolate the router management interface from untrusted networks
• Monitor for exploitation attempts using the detection strategies outlined above
• Consider replacing affected devices with models from vendors with better security update practices

Patch Information

As of the last modification date (2026-02-27), no official patch has been released by Tenda for this vulnerability. Users should monitor the Tenda Company Homepage for firmware updates. Given Tenda's history with router vulnerabilities, users may need to consider alternative mitigation strategies if patches are not forthcoming.

Workarounds

• Disable the web management interface entirely and use alternative management methods if available
• Configure firewall rules to block external access to the router's management ports (typically port 80/443)
• Implement strong authentication and change default credentials to reduce the attack surface
• Place the router behind an additional firewall that can filter malicious requests to the management interface

# Example iptables rules to restrict management interface access
# Allow management access only from trusted admin workstation
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.100 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.100 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP