Overview
CVE-2025-6334 is a critical vulnerability discovered in the D-Link DIR-867 1.0 router. This flaw has the potential to compromise systems, leading to possible data leakage. The vulnerability lies in the strncpy function of the Query String Handler component of the D-Link DIR-867 1.0 router. The exploit has been disclosed publicly and is of a critical nature, due to the potential for remote execution. This vulnerability only affects this specific product, which is no longer supported by the vendor, increasing the level of risk involved.
Vulnerability Summary
CVE ID: CVE-2025-6334
Severity: Critical (8.8 CVSS Score)
Attack Vector: Remote
Privileges Required: None
User Interaction: None
Impact: Potential system compromise and data leakage.
Affected Products
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Product | Affected Versions
D-Link DIR-867 | 1.0
How the Exploit Works
The vulnerability comes into play in the strncpy function of the Query String Handler component of the D-Link DIR-867 1.0 router. The manipulation of this function leads to a stack-based buffer overflow. An attacker can remotely exploit this vulnerability to run arbitrary code on the compromised system, leading to a complete system compromise or potential data leakage.
Conceptual Example Code
The following conceptual code represents how the vulnerability might be exploited. This is a malicious payload sent via an HTTP POST request to the vulnerable endpoint on the router:
POST /vulnerable/endpoint HTTP/1.1
Host: target.router.com
Content-Type: application/json
{
"malicious_payload": "strncpy(buffer, overly_long_string, size_of_buffer);"
}In this payload, the “overly_long_string” would be replaced with an actual string that is longer than the “size_of_buffer”. This would trigger the buffer overflow, potentially leading to arbitrary code execution.
Please note that this is a conceptual representation and the actual exploit may vary based on the specific conditions of the target network, the configuration of the affected device, and the intent of the attacker.
Mitigation
Given that the product is no longer supported by the vendor, applying a vendor patch is not possible. As a temporary mitigation, users can employ a Web Application Firewall (WAF) or Intrusion Detection System (IDS). These systems can help detect and possibly prevent the exploitation of this vulnerability. It is, however, recommended to replace the unsupported device with a supported one as soon as possible for a more permanent solution.