Overview
This article analyzes CVE-2025-65226, a buffer overflow vulnerability discovered in the Tenda AC21 router, specifically version V16.03.08.16. This vulnerability exists within the /goform/saveParentControlInfo endpoint and is triggered by manipulating the deviceId parameter. Exploitation of this vulnerability could allow an attacker to potentially execute arbitrary code on the affected device.
Technical Details
The vulnerability lies within the handling of the deviceId parameter within the /goform/saveParentControlInfo endpoint of the Tenda AC21 router’s firmware. It appears that the input validation for the deviceId parameter is insufficient. Sending an overly long string as the value for the deviceId parameter causes a buffer overflow, overwriting adjacent memory regions. This could lead to denial of service (DoS) or, in more sophisticated attacks, remote code execution (RCE).
CVSS Analysis
Currently, the CVE entry (CVE-2025-65226) does not list a CVSS score. This might be because the vulnerability is newly discovered or still under analysis. A CVSS score will provide a standardized way to assess the severity and potential impact of this vulnerability. Without a CVSS score, assessing the potential impact is challenging. However, buffer overflows generally have the potential for high severity due to the possibility of remote code execution.
Possible Impact
The impact of exploiting CVE-2025-65226 could be significant. A successful exploit could lead to:
- Denial of Service (DoS): The router could crash, rendering it unusable for legitimate users.
- Remote Code Execution (RCE): An attacker could execute arbitrary code on the router, potentially gaining full control of the device. This could allow the attacker to intercept network traffic, modify router settings, or use the router as a bot in a botnet.
- Data Breaches: If the attacker gains control of the router, they could potentially access sensitive data stored on the network or intercept communications.
Mitigation or Patch Steps
Currently, there is no official patch or mitigation released by Tenda for CVE-2025-65226. The following steps are recommended to mitigate the risk:
- Monitor Tenda’s website for firmware updates: Check the official Tenda website regularly for new firmware releases that address this vulnerability.
- Disable Remote Management: If possible, disable remote management of the router to reduce the attack surface.
- Use a Strong Password: Ensure that a strong, unique password is set for the router’s administration interface.
- Network Segmentation: Segment your network to limit the impact of a compromised router.
- Contact Tenda Support: Reach out to Tenda support and inquire about a patch for this specific vulnerability.
