CVE-2025-20683: Local Privilege Escalation Due to Incorrect Bounds Check in WLAN AP Driver

Overview

CVE-2025-20683 is a severe security vulnerability that could affect any user who has not yet updated their wireless LAN AP driver. The vulnerability lies in the incorrect bounds check in the WLAN AP driver that could lead to an out-of-bounds write, providing an opportunity for a potential attacker to exploit the system. If successfully exploited, this could result in an unwanted escalation of privileges, even leading to system compromise or data leakage. With a high CVSS severity score of 9.8, it is imperative that users understand the potential risks associated with this vulnerability and take immediate action to mitigate the risks.

Vulnerability Summary

CVE ID: CVE-2025-20683
Severity: Critical, CVSS score of 9.8
Attack Vector: Local
Privileges Required: User level
User Interaction: Not needed
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

WLAN AP Driver | All versions prior to the patch

How the Exploit Works

The exploit takes advantage of an incorrect bounds check in the WLAN AP driver. This faulty check allows for an out-of-bounds write, which could then be used to execute arbitrary code with user execution privileges. This could lead to an attacker gaining escalated privileges and potentially compromising the system or leaking data.

Conceptual Example Code

To illustrate how this vulnerability might be exploited, consider the following pseudocode:

#include <stdio.h>
#include <string.h>
void vulnerable_function(char *input) {
char buffer[1024];
strcpy(buffer, input); // no bounds checking
}
int main() {
char exploit_input[2048];
memset(exploit_input, 'A', 2048); // fill with 'A'
vulnerable_function(exploit_input); // buffer overflow
return 0;
}

In this example, a buffer of size 1024 is created. However, the strcpy function is used to copy the user’s input into this buffer without checking if the size of the user’s input exceeds the size of the buffer. This leads to a buffer overflow, which could be exploited for arbitrary code execution and privilege escalation.

Mitigation

To mitigate this vulnerability, users are advised to apply the vendor patch identified as WCNCR00416938. If for some reason the patch cannot be applied immediately, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) could serve as a temporary mitigation strategy. However, these measures are not foolproof and the patch should be applied as soon as possible to ensure maximum security.