CVE-2021-33536 Explained : Impact and Mitigation

Industrial WLAN devices manufactured by Weidmüller are affected by a significant denial-of-service vulnerability. The vulnerability exists in the ServiceAgent functionality of multiple versions, allowing an attacker to exploit it using specially crafted packets. Read on to understand the impact, technical details, and mitigation methods related to CVE-2021-33536.

Understanding CVE-2021-33536

This section provides insights into the nature of the vulnerability affecting Weidmüller Industrial WLAN devices.

What is CVE-2021-33536?

The CVE-2021-33536 vulnerability is a denial-of-service issue present in Weidmüller Industrial WLAN devices due to an exploitable flaw in the ServiceAgent functionality.

The Impact of CVE-2021-33536

The vulnerability poses a high risk as it can be triggered by an attacker using a specially crafted packet, potentially leading to a denial-of-service condition. The CVSS base score of this vulnerability is 7.5 (High Severity).

Technical Details of CVE-2021-33536

Explore the detailed technical aspects of the CVE-2021-33536 vulnerability affecting Weidmüller Industrial WLAN devices.

Vulnerability Description

The vulnerability involves an integer underflow that can be exploited to trigger a large memcpy operation, resulting in the access of unmapped or out-of-bounds memory, causing a denial-of-service condition.

Affected Systems and Versions

Weidmüller Industrial WLAN devices versions IE-WL-BL-AP-CL-EU, IE-WLT-BL-AP-CL-EU, IE-WL-BL-AP-CL-US, IE-WLT-BL-AP-CL-US, IE-WL-VL-AP-BR-CL-EU, IE-WLT-VL-AP-BR-CL-EU, IE-WL-VL-AP-BR-CL-US, and IE-WLT-VL-AP-BR-CL-US are affected by this vulnerability.

Exploitation Mechanism

The vulnerability can be exploited by sending a specially crafted packet without the need for authentication, causing an integer underflow and triggering the denial-of-service condition.

Mitigation and Prevention

Learn about the steps to mitigate the CVE-2021-33536 vulnerability affecting Weidmüller Industrial WLAN devices.

Immediate Steps to Take

To address the vulnerability, users are advised to update their IE-WL(T)-BL-AP-CL-XX and IE-WL(T)-VL-AP-CL-XX devices to versions V1.16.21 (Build 21010513) and V1.11.13 (Build 21010513) or newer, respectively.

Long-Term Security Practices

Incorporate best security practices such as network segmentation, regular security audits, and employee training to enhance the overall security posture of Industrial WLAN devices.

Patching and Updates

Ensure timely installation of patches and updates provided by Weidmüller to address known vulnerabilities and enhance the security of Industrial WLAN devices.