CVE-2026-3272: Tenda F453 Firmware Buffer Overflow Flaw

CVE-2026-3272 Overview

A buffer overflow vulnerability has been identified in Tenda F453 routers running firmware version 1.0.0.3. The vulnerability exists in the fromDhcpListClient function within the /goform/DhcpListClient endpoint of the httpd component. An attacker can manipulate the page argument to trigger a buffer overflow condition, potentially leading to remote code execution or denial of service. The exploit has been publicly disclosed, making this vulnerability a significant security concern for organizations using affected devices.

Critical Impact

Remote attackers with low privileges can exploit this buffer overflow vulnerability over the network 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

Discovery Timeline

• 2026-02-27 - CVE-2026-3272 published to NVD
• 2026-02-27 - Last updated in NVD database

Technical Details for CVE-2026-3272

Vulnerability Analysis

This vulnerability is classified as a buffer overflow (CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer). The vulnerable function fromDhcpListClient fails to properly validate the length of user-supplied input in the page parameter before copying it into a fixed-size buffer. This lack of bounds checking allows an attacker to overflow the buffer, potentially overwriting adjacent memory regions.

The vulnerability is remotely exploitable over the network and requires only low-level privileges to execute. No user interaction is required, making automated exploitation feasible. Successful exploitation could result in complete compromise of confidentiality, integrity, and availability of the affected device.

Root Cause

The root cause of CVE-2026-3272 is improper input validation in the fromDhcpListClient function within the httpd service. The function processes the page argument from HTTP requests to the /goform/DhcpListClient endpoint without adequately checking input length boundaries. When an oversized value is submitted, the function copies the data into a stack or heap buffer without proper bounds checking, resulting in a classic buffer overflow condition.

Attack Vector

The attack vector for this vulnerability is network-based, targeting the httpd web service running on the Tenda F453 router. An authenticated attacker can send a specially crafted HTTP request to the /goform/DhcpListClient endpoint with a malicious page parameter value. The oversized input triggers the buffer overflow in the fromDhcpListClient function.

The vulnerability can be exploited by sending a crafted HTTP POST or GET request to the vulnerable endpoint. The page parameter accepts user input that is processed by the vulnerable function without proper length validation. By providing an excessively long string, attackers can overwrite memory beyond the allocated buffer boundaries, potentially gaining control of program execution flow.

Technical details and proof-of-concept information are available in the GitHub Vulnerability Database Entry.

Detection Methods for CVE-2026-3272

Indicators of Compromise

• Unusual or malformed HTTP requests targeting /goform/DhcpListClient with abnormally long page parameter values
• Unexpected httpd service crashes or restarts on Tenda F453 devices
• Network traffic containing excessively large payloads directed at router management interfaces
• Anomalous system behavior or configuration changes on affected routers

Detection Strategies

• Deploy network intrusion detection systems (IDS) with signatures to detect buffer overflow attempts targeting /goform/DhcpListClient
• Monitor HTTP request logs for requests with unusually long parameter values to the vulnerable endpoint
• Implement web application firewall (WAF) rules to block requests with oversized input parameters
• Enable logging on network devices to capture and analyze traffic to Tenda router management interfaces

Monitoring Recommendations

• Regularly review system logs from Tenda F453 devices for signs of exploitation attempts or abnormal crashes
• Set up alerts for httpd service failures or unexpected reboots on affected devices
• Monitor network traffic patterns for reconnaissance activity targeting router endpoints
• Implement network segmentation to limit access to router management interfaces from untrusted networks

How to Mitigate CVE-2026-3272

Immediate Actions Required

• Restrict access to the router's web management interface to trusted networks only using firewall rules
• Disable remote management features if not required for operations
• Implement network segmentation to isolate affected devices from untrusted network segments
• Monitor for exploitation attempts using network detection tools

Patch Information

At the time of publication, no official patch from Tenda has been identified for this vulnerability. Organizations should monitor the Tenda Official Website for firmware updates and security advisories. Additional vulnerability tracking information is available through VulDB #347996.

Workarounds

• Restrict management interface access to specific trusted IP addresses using access control lists (ACLs)
• Disable the web management interface entirely if feasible and manage devices through alternative secure methods
• Place affected devices behind a firewall that filters malicious HTTP requests
• Consider replacing vulnerable devices with alternative hardware if patches are not forthcoming

Implement the following access restrictions on your network firewall to limit exposure:

# Configuration example
# Restrict access to Tenda router management interface
# Allow only trusted management subnet
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP

# Block access to vulnerable endpoint from external networks
iptables -A INPUT -p tcp --dport 80 -m string --string "/goform/DhcpListClient" --algo bm -j DROP