Overview
The cyber landscape is constantly evolving, with new vulnerabilities cropping up regularly. One such vulnerability that has become a cause of concern is the CVE-2025-5902, which affects TOTOLINK T10 routers. This critical flaw could potentially lead to system compromise or data leakage, affecting all users of the vulnerable router version. Given its severity and how widespread these routers are, it’s crucial to understand the nature of this vulnerability and how to mitigate it.
Vulnerability Summary
CVE ID: CVE-2025-5902
Severity: Critical, CVSS Score 8.8
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 T10 | 4.1.8cu.5207
How the Exploit Works
The vulnerability lies within the setUpgradeFW function of the /cgi-bin/cstecgi.cgi file. Specifically, the issue arises from the manipulation of the “slaveIpList” argument, which leads to a buffer overflow. This buffer overflow may be exploited by a malicious actor to execute arbitrary code on the device, potentially leading to system compromise or data leakage. The exploit can be initiated remotely, meaning that an attacker doesn’t need physical access to the device to carry out the attack.
Conceptual Example Code
Here’s a conceptual example of how the vulnerability might be exploited:
POST /cgi-bin/cstecgi.cgi HTTP/1.1
Host: target.example.com
Content-Type: application/json
{
"slaveIpList": "A string longer than the buffer that causes an overflow..."
}In this example, the “slaveIpList” argument is filled with a string that’s longer than the buffer can handle, causing it to overflow. This overflow can then be used to execute arbitrary code.
Mitigation
The best way to protect your systems from this vulnerability is to apply the patch released by the vendor. If for some reason you are unable to apply the patch immediately, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can offer some temporary mitigation. These systems can help detect and block attempts to exploit this vulnerability until the patch can be applied.
In the long term, it’s essential to keep your systems updated and patched against known vulnerabilities. Regular security audits can also help identify and mitigate potential vulnerabilities before they can be exploited.