Executive Intelligence Brief

A critical vulnerability has been identified in the Tenda AC1206 router, which could allow remote attackers to exploit a stack-based buffer overflow in the httpd web management interface. This vulnerability, tracked as CVE-2026-19788, has a CVSS score of 8.8, indicating a high severity level. The affected device is widely used in various networks, and the exploit has been made public, increasing the likelihood of active exploitation. Immediate patching or mitigation is recommended for organizations using the affected version (15.03.06.23_multi_TD01).

Threat Overview

The Tenda AC1206 is a popular wireless router used for home and small office networks. It provides various features such as wireless connectivity, multiple Ethernet ports, and a web-based management interface for configuration and monitoring. The device is widely deployed due to its affordability and ease of use.

The vulnerability affects the set_device_name function in the /goform/SetOnlineDevName file of the httpd web management interface. The manipulation of the devName argument results in a stack-based buffer overflow, allowing remote attackers to potentially execute arbitrary code or crash the device.

Technical Deep Dive

Vulnerability Classification

The vulnerability is classified as a stack-based buffer overflow (CWE-119 and CWE-121). This type of vulnerability occurs when more data is written to a buffer than it is designed to hold, causing the extra data to spill over into adjacent areas of memory. In this case, the vulnerability is triggered by manipulating the devName argument in the /goform/SetOnlineDevName file.

Root Cause Analysis

The root cause of this vulnerability is the lack of proper input validation and bounds checking in the set_device_name function. The function does not adequately verify the length of the devName argument, allowing attackers to overflow the buffer with malicious data.

Attack Vector & Chain

The attack vector for this vulnerability is remote and unauthenticated. An attacker can exploit this vulnerability by sending a crafted request to the /goform/SetOnlineDevName endpoint with a specially designed devName argument. The attack requires low privileges and no user interaction.

Exploitation Scenario Walkthrough

Scenario: Remote Code Execution via Stack-Based Buffer Overflow

Reconnaissance: An attacker discovers a vulnerable Tenda AC1206 router with the affected firmware version (15.03.06.23_multi_TD01) using a network scanning tool or by searching for exposed devices on the internet.

Weaponization: The attacker crafts a malicious request with a specially designed devName argument that overflows the buffer in the set_device_name function.

Delivery & Exploitation: The attacker sends the crafted request to the /goform/SetOnlineDevName endpoint, triggering the buffer overflow and potentially allowing remote code execution or device crashes.

Post-Exploitation: If the attacker successfully exploits the vulnerability, they may execute arbitrary code on the device, potentially gaining control over the router. This could lead to further malicious activities such as data exfiltration, network lateral movement, or the deployment of malware.

Impact Realization: The final impact of this vulnerability could be significant, as an attacker could use it to gain unauthorized access to the network, intercept sensitive data, or disrupt network operations.

Exploitation in the Wild

The exploit for CVE-2026-19788 has been made public, but there is no indication of active exploitation in the wild at this time. However, the public availability of the exploit increases the risk of future attacks.

Impact Analysis

Direct Impact

The direct impact of this vulnerability is a stack-based buffer overflow in the httpd web management interface of the Tenda AC1206 router. This could lead to remote code execution, device crashes, or data corruption.

Downstream & Cascading Effects

The downstream effects of this vulnerability could include:

  • Unauthorized access to the network and sensitive data
  • Deployment of malware or ransomware
  • Disruption of network operations and services
  • Potential lateral movement to other devices on the network

Affected Products & Versions

The affected product is the Tenda AC1206 router with firmware version 15.03.06.23_multi_TD01.

Detection & Threat Hunting

Indicators of Compromise

No specific indicators of compromise (IoCs) are provided in the source data. However, organizations can monitor for suspicious activity such as:

  • Unusual requests to the /goform/SetOnlineDevName endpoint
  • Anomalous network traffic patterns
  • Device crashes or reboots

Detection Rules & Signatures

Detection rules can be created to monitor for suspicious activity related to this vulnerability. For example:

  • Monitor HTTP requests to the /goform/SetOnlineDevName endpoint
  • Detect anomalies in network traffic patterns

Threat Hunting Queries

Threat hunting queries can be used to identify potential exploitation attempts. For example:

  • Search for requests to the /goform/SetOnlineDevName endpoint with suspicious parameters
  • Analyze network traffic for anomalies

Remediation & Hardening

Immediate Actions (0-24 hours)

Organizations using the affected Tenda AC1206 router should:

  • Apply patches or updates provided by the vendor (if available)
  • Implement workarounds such as restricting access to the /goform/SetOnlineDevName endpoint
  • Monitor for suspicious activity

Short-Term Hardening (1-7 days)

In addition to immediate actions, organizations should:

  • Implement network segmentation to limit the spread of potential attacks
  • Enhance monitoring and logging to detect suspicious activity
  • Restrict access to the web management interface

Strategic Recommendations

To prevent similar vulnerabilities in the future, organizations should:

  • Regularly update and patch devices
  • Implement a robust vulnerability management program
  • Conduct regular security audits and penetration testing

Analyst Assessment

The risk of exploitation for CVE-2026-19788 is high due to the public availability of the exploit and the severity of the vulnerability. Organizations using the affected Tenda AC1206 router should prioritize patching or mitigation efforts to prevent potential attacks.

Sources

  • National Vulnerability Database (NVD) - CVE-2026-19788