Overview
A high-severity buffer overflow vulnerability, identified as CVE-2025-13400, has been discovered in Tenda CH22 routers, version 1.0.0.1. This vulnerability allows a remote attacker to potentially execute arbitrary code on the device. The exploit for this vulnerability is now publicly available, increasing the risk of exploitation.
Technical Details
The vulnerability lies within the formWrlExtraGet function in the /goform/WrlExtraGet file. Specifically, the vulnerability is triggered when manipulating the chkHz argument. By sending a specially crafted request with an overly long chkHz value, an attacker can overwrite the buffer, potentially leading to arbitrary code execution.
CVSS Analysis
- CVE ID: CVE-2025-13400
- Severity: HIGH
- CVSS Score: 8.8
A CVSS score of 8.8 indicates a high-severity vulnerability. This score reflects the ease of exploitation (remote exploitation possible) and the potential impact (arbitrary code execution).
Possible Impact
Successful exploitation of CVE-2025-13400 could have significant consequences, including:
- Remote Code Execution (RCE): An attacker could execute arbitrary code on the affected router, gaining control of the device.
- Data Theft: An attacker could potentially access sensitive data stored on the router or network.
- Denial of Service (DoS): The router could be rendered unusable, disrupting network connectivity.
- Malware Propagation: The compromised router could be used to spread malware to other devices on the network.
Mitigation or Patch Steps
The best course of action is to apply the official patch from Tenda as soon as it becomes available. Here are some general mitigation steps:
- Check for Firmware Updates: Regularly check the Tenda support website (https://www.tenda.com.cn/) for firmware updates that address this vulnerability.
- Disable Remote Management: If possible, disable remote management access to the router. This can reduce the attack surface.
- Use a Strong Password: Ensure a strong and unique password is set for the router’s administrative interface.
- Monitor Network Traffic: Monitor network traffic for suspicious activity that could indicate an attempted exploit.
- Consider a Firewall: Implement a firewall to filter potentially malicious traffic.
