Overview
The CVE-2025-6158 vulnerability is a severe security flaw identified in D-Link DIR-665 1.00. This vulnerability, classified as critical, impacts the HTTP POST Request Handler component, specifically the sub_AC78 function. The manipulation of this function can lead to a stack-based buffer overflow, potentially compromising the system or leading to data leakage.
Importantly, this vulnerability affects products that are no longer supported by the maintainer, making it particularly concerning for those using outdated versions of the product. With the exploit already disclosed to the public, users of the affected products are strongly advised to take immediate corrective measures to protect their systems.
Vulnerability Summary
CVE ID: CVE-2025-6158
Severity: Critical (8.8 CVSS Severity Score)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise and potential data leakage
Affected Products
Escape the Surveillance Era
Most apps won’t tell you the truth.
They’re part of the problem.
Phone numbers. Emails. Profiles. Logs.
It’s all fuel for surveillance.
Ameeba Chat gives you a way out.
- • No phone number
- • No email
- • No personal info
- • Anonymous aliases
- • End-to-end encrypted
Chat without a trace.
Product | Affected Versions
D-Link DIR-665 | 1.00
How the Exploit Works
The exploit works by sending a manipulated HTTP POST request to the sub_AC78 function of the affected product. This oversizes the input buffer, leading to a stack-based buffer overflow. This overflow can then be exploited to execute arbitrary code on the system, thereby compromising it. The vulnerability can be exploited remotely and does not require any user interaction, making it particularly dangerous.
Conceptual Example Code
The following is a conceptual example of how the vulnerability might be exploited:
POST /vulnerable/sub_AC78 HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "malicious_payload": "A"*4096 }In this example, the malicious payload is a string of 4096 ‘A’ characters, designed to overrun the buffer and trigger the overflow.
Mitigation Guidance
Users of the affected product are advised to apply the vendor patch as soon as possible. If the patch cannot be applied immediately, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation measure. However, these are not full-proof solutions and can only minimize the risk. The ultimate solution is to update the product or replace it with one that is currently supported by the vendor.