Overview
A critical vulnerability has been discovered in Tenda O3V2 1.0.0.12(3880), referred to in the Common Vulnerabilities and Exposures system as CVE-2025-7421. This vulnerability lies within the fromMacFilterModify function of the /goform/operateMacFilter file, specifically in the component httpd. The result of this vulnerability is a stack-based buffer overflow that can be exploited remotely. This presents a significant risk to any system running Tenda O3V2 1.0.0.12(3880) due to the potential for system compromise or data leakage.
Vulnerability Summary
CVE ID: CVE-2025-7421
Severity: Critical (CVSS 8.8)
Attack Vector: Remote
Privileges Required: None
User Interaction: None
Impact: System compromise, potential data leakage
Affected Products
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Product | Affected Versions
Tenda O3V2 | 1.0.0.12(3880)
How the Exploit Works
The vulnerability stems from improper handling of the ‘mac’ argument in the fromMacFilterModify function. This improper handling leads to a stack-based buffer overflow. The attacker, by sending a specially crafted request with a manipulated ‘mac’ argument, can trigger the overflow, which then allows them to execute arbitrary code within the context of the application.
Conceptual Example Code
Here’s a conceptual example of how the vulnerability might be exploited. This could be a sample HTTP request:
POST /goform/operateMacFilter HTTP/1.1
Host: target.example.com
Content-Type: application/x-www-form-urlencoded
mac=01:23:45:67:89:ab;payload_that_triggers_buffer_overflowMitigation Recommendations
The vendor has provided a patch to fix this vulnerability. It is highly recommended to apply this patch as soon as possible. Until the patch can be applied, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide some level of temporary mitigation. However, these measures will not fully protect against the exploit and should only be used as a short-term solution while patching is underway.