Overview
The cybersecurity world has yet again been hit with a new vulnerability, CVE-2025-9780, that affects TOTOLINK A702R 4.0.0-B20211108.1423. This vulnerability is significant due to the potential system compromise or data leakage that could occur if exploited. It’s important for users and administrators of this software to understand the depth of this issue as it affects a popular function, sub_419BE0, in the file /boafrm/formIpQoS. With the exploit being published and available for use, it has become even more critical to understand and mitigate this vulnerability.
Vulnerability Summary
CVE ID: CVE-2025-9780
Severity: High (CVSS: 8.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise and potential data leakage
Affected Products
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Product | Affected Versions
TOTOLINK A702R | 4.0.0-B20211108.1423
How the Exploit Works
The flaw in the TOTOLINK A702R stems from a buffer overflow vulnerability that happens due to incorrect handling of the ‘mac’ argument in the function ‘sub_419BE0’ of the file ‘/boafrm/formIpQoS’. When malformed or oversized data is input into the ‘mac’ argument, the buffer overflows, causing erratic program behavior or even allowing an attacker to execute arbitrary code.
Conceptual Example Code
Here’s a conceptual example of an HTTP request that could exploit this vulnerability:
POST /boafrm/formIpQoS HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "mac": "OVERSIZED_INPUT_DATA" }In this example, “OVERSIZED_INPUT_DATA” represents a value that is larger than the buffer assigned to the ‘mac’ argument. When this data is processed, it overflows the buffer, leading to the vulnerability.
Mitigation Guidance
In order to mitigate this vulnerability, it is recommended to apply the vendor patch as soon as it is available. As an interim solution, the use of a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can help identify and block attempts to exploit this vulnerability. Please note that these are temporary measures and applying the vendor patch should be the ultimate goal to secure your system.
