Overview
A critical vulnerability, designated as CVE-2025-5912, has been identified in D-Link DIR-632 FW103B08. This vulnerability carries significant weight as it affects the function do_file of the HTTP POST Request Handler component. The exploitation of this vulnerability could potentially lead to a system compromise or data leakage, making it a matter of grave concern for the cybersecurity community. It is particularly alarming because the exploit is publicly disclosed and may be used, and it affects products no longer supported by the maintainer, which means they are unlikely to receive patches or updates.
Vulnerability Summary
CVE ID: CVE-2025-5912
Severity: Critical (CVSS score 8.8)
Attack Vector: Network (Remote)
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 lies in the function do_file within the HTTP POST Request Handler of the D-Link DIR-632 router firmware. An attacker can remotely send a maliciously crafted HTTP POST request to this function, causing a stack-based buffer overflow. This occurrence can lead to arbitrary code execution on the device, resulting in a system compromise. Given that the exploit can be initiated remotely and without any user interaction, this vulnerability presents a significant security risk.
Conceptual Example Code
Here is a conceptual example of an HTTP POST request that could potentially exploit this vulnerability:
POST /do_file HTTP/1.1
Host: vulnerable.router.ip
Content-Type: application/octet-stream
{ "malicious_payload": "OVERFLOWING_DATA" }In this example, the “malicious_payload” contains data that exceeds the buffer’s capacity, causing a buffer overflow. The overflowing data may contain malicious instructions that the system executes unknowingly.
Mitigation
Given that the affected products are no longer supported by the maintainer, the primary course of action to mitigate this vulnerability is to apply any available vendor patches. If no patches are available, it is recommended to use a Web Application Firewall (WAF) or Intrusion Detection System (IDS) as temporary mitigation. Users are also advised to replace the affected devices with those that are currently supported and receiving security updates.