Overview
The cybersecurity landscape is constantly evolving, and a new vulnerability, classified as critical, has been identified in the D-Link DIR-632 FW103B08. This vulnerability, identified as CVE-2025-5969, affects an unsupported product, increasing the risk for users who are still using it. Given the severity of this vulnerability, it is important to understand its implications, who it affects, and how it can be mitigated. This vulnerability is significant due to its potential for system compromise and data leakage, and the fact that it can be exploited remotely, increasing the pool of potential attackers.
Vulnerability Summary
CVE ID: CVE-2025-5969
Severity: Critical – CVSS Severity 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
D-Link DIR-632 FW103B08 | All versions
How the Exploit Works
The vulnerability is a stack-based buffer overflow issue found in the function FUN_00425fd8 of the file /biurl_grou of the HTTP POST Request Handler. An attacker can exploit this vulnerability by sending a specially crafted HTTP POST request to the affected device, which will cause an overflow in the stack buffer. This overflow can allow the attacker to execute arbitrary code on the device, thus compromising the system and potentially leading to data leakage.
Conceptual Example Code
Below is a conceptual example of how the vulnerability might be exploited. This is an example of a malicious HTTP POST request:
POST /biurl_grou HTTP/1.1
Host: target.example.com
Content-Type: application/x-www-form-urlencoded
data=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA...In this example, the ‘data’ parameter is filled with an excessive number of characters (‘A’ in this case), causing a buffer overflow.
Recommended Mitigation
Mitigation of this vulnerability involves applying the patch provided by the vendor. However, since the product is no longer supported by the maintainer, users of the affected product are strongly recommended to upgrade to a supported version. As a temporary mitigation, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can be used to detect and block attempts to exploit this vulnerability.