Overview
A severe vulnerability has been identified in the Tenda AC21 software version 16.03.08.16 that exposes systems to potential compromise or data leakage. This cybersecurity threat, denoted as CVE-2025-10838, specifically affects the function sub_45BB10 of the file /goform/WifiExtraSet, leading to buffer overflow when the argument wpapsk_crypto is manipulated. Given the widespread use of Tenda AC21 in various network environments, this vulnerability could potentially impact a large number of systems and is, therefore, a critical concern for cybersecurity professionals.
Vulnerability Summary
CVE ID: CVE-2025-10838
Severity: Critical (CVSS: 8.8)
Attack Vector: Remote
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage
Affected Products
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Product | Affected Versions
Tenda AC21 | 16.03.08.16
How the Exploit Works
The exploit takes advantage of a buffer overflow vulnerability in the Tenda AC21’s function sub_45BB10 of the file /goform/WifiExtraSet. The vulnerability arises when an attacker remotely manipulates the argument wpapsk_crypto, causing the program to write more data into the buffer than it can handle. This overflow can lead to system crashes, incorrect calculations, or even allow an attacker to execute arbitrary code, potentially leading to full system compromise.
Conceptual Example Code
Consider the following conceptual HTTP request that an attacker might use to exploit this vulnerability:
POST /goform/WifiExtraSet HTTP/1.1
Host: target.example.com
Content-Type: application/x-www-form-urlencoded
wpapsk_crypto=A_LONG_STRING_THAT_CAUSES_BUFFER_OVERFLOWThis request attempts to overflow the buffer by sending a longer string than expected for the wpapsk_crypto argument. If the server is not properly protected, this could lead to system compromise or data leakage.
Mitigation
To mitigate this vulnerability, users are advised to apply the vendor’s patch once it becomes available. In the meantime, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can be used as temporary mitigation measures to protect the system from potential attacks exploiting this vulnerability.
