CVE-2025-20684: Potential Escalation of Privilege in WLAN AP Driver

Overview

CVE-2025-20684 is a critical vulnerability that exists in the WLAN AP driver, which, if exploited, can lead to a local escalation of privilege. The vulnerability lies in an incorrect bounds check which can result in an out of bounds write. It’s a significant issue because it doesn’t require any user interaction for exploitation, and it could potentially compromise the system or lead to data leakage. Entities that are reliant on the affected driver, especially those dealing with sensitive data, must pay close attention to this vulnerability as its successful exploitation could have severe consequences.

Vulnerability Summary

CVE ID: CVE-2025-20684
Severity: Critical – CVSS Score 9.8
Attack Vector: Local
Privileges Required: User
User Interaction: None
Impact: Local escalation of privilege leading to potential system compromise or data leakage.

Affected Products

Product | Affected Versions

WLAN AP Driver | All versions before patch WCNCR00416939

How the Exploit Works

The vulnerability stems from a failure in the bounds check mechanism within the WLAN AP driver. This flawed mechanism allows an attacker to write data beyond the allocated memory space-an out-of-bounds write. This action can lead to memory corruption or even a crash, but more critically, it can allow an attacker to execute arbitrary code with user privileges. With this level of access, an attacker can potentially gain control over the system or access sensitive data.

Conceptual Example Code

Here’s a
conceptual
example of how the vulnerability might be exploited using pseudocode:

# Assuming the attacker already has user access on the system
def exploit_CVE_2025_20684():
# Create an oversized payload
payload = create_payload(OVERSIZED)
# Write the payload to the vulnerable driver
write_to_driver("WLAN AP Driver", payload)
# The payload is now executed with user privileges
execute_payload(payload)

This pseudocode illustrates an attacker creating an oversized payload, writing this payload to the WLAN AP driver-exploiting the incorrect bounds check, and then executing the payload with user privileges.

Mitigation Guidance

The best mitigation for this vulnerability is to apply the vendor patch identified as WCNCR00416939. If immediate application of the patch is not possible, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as temporary mitigation. These systems should be configured to detect and block attempts to exploit this vulnerability. Furthermore, it is advisable to follow the principle of least privilege, ensuring user accounts have the minimum level of access necessary, reducing the potential impact of this vulnerability.