Overview
In the realm of cybersecurity, vulnerabilities are a common occurrence that can open up systems to malicious attacks. One such vulnerability has been discovered in Tenda O3V2 1.0.0.12(3880), a popular networking device. This vulnerability, designated as CVE-2025-7420, is particularly concerning due to its critical nature and the potential for remote attacks leading to system compromise or data leakage.
The vulnerability resides in the function formWifiBasicSet of the file /goform/setWrlBasicInfo of the httpd component. It is significant as it affects a wide range of systems running this software version and can be exploited remotely, leading to a stack-based buffer overflow. This makes it a pressing concern for cybersecurity professionals and system administrators alike.
Vulnerability Summary
CVE ID: CVE-2025-7420
Severity: Critical, CVSS Score 8.8
Attack Vector: Remote
Privileges Required: None
User Interaction: None
Impact: System compromise and 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 arises from improper handling of the ‘extChannel’ argument within the ‘formWifiBasicSet’ function. A remote attacker can exploit this by sending specially crafted input to the ‘extChannel’ argument. This results in a stack-based buffer overflow, which can lead to arbitrary code execution. In essence, the attacker can manipulate the system as per their malicious intent, potentially leading to system compromise or data leakage.
Conceptual Example Code
Here is a conceptual example of a malicious HTTP request that could exploit this vulnerability:
POST /goform/setWrlBasicInfo HTTP/1.1
Host: vulnerable-tenda-o3v2-device
Content-Type: application/x-www-form-urlencoded
extChannel=AAAA...[long string of A's to overflow buffer]...Remediation
The best course of action is to apply the patch provided by the vendor as soon as possible. This patch addresses the vulnerability and prevents its exploitation. In the meantime, until the patch can be applied, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide a temporary mitigation, monitoring and blocking any suspicious activity related to this vulnerability.