Overview
In the continuous pursuit of a secure digital environment, acknowledging and addressing vulnerabilities is key. The latest vulnerability to be taken into account is CVE-2025-45861. This severe flaw resides in the TOTOLINK A3002R v4.0.0-B20230531.1404 router and can potentially compromise the entire system or lead to data leakage. This vulnerability is particularly alarming due to its high severity score, which pinpoints the critical risk associated with it. It is essential for concerned users and cybersecurity professionals to understand this vulnerability, its effects, and the steps necessary to mitigate it.
Vulnerability Summary
CVE ID: CVE-2025-45861
Severity: Critical (9.8/10.0)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage
Affected Products
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Product | Affected Versions
TOTOLINK A3002R | v4.0.0-B20230531.1404
How the Exploit Works
The exploit works through a buffer overflow in the formDnsv6 interface of the TOTOLINK A3002R router. Specifically, the routername parameter is susceptible to this overflow. An attacker can send crafted packets that exceed the expected input, causing the buffer to overflow. This overflow could then allow the attacker to execute arbitrary code or disrupt the normal operation of the router, potentially leading to system compromise or data leakage.
Conceptual Example Code
This is a conceptual example demonstrating how a malicious payload might be sent to the vulnerable endpoint:
POST /formDnsv6 HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "routername": "regularname" + "A"*5000 }In this example, the “routername” parameter is filled with a valid routername, followed by a string of ‘A’ characters that’s long enough to overflow the buffer.
Recommended Mitigation
The best way to mitigate this vulnerability is to apply the vendor’s patch as soon as it becomes available. In the meantime, or if a patch is not available, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can be used to detect and block attempts to exploit this vulnerability.