CVE-2021-33539
CWE-287Published: June 25, 2021· Updated: Jun 17, 2026
Official Description
In Weidmueller Industrial WLAN devices in multiple versions an exploitable authentication bypass vulnerability exists in the hostname processing. A specially configured device hostname can cause the device to interpret selected remote traffic as local traffic, resulting in a bypass of web authentication. An attacker can send authenticated SNMP requests to trigger this vulnerability.
Technical Analysis
CVE-2021-33539 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.2.
From a weakness classification perspective (CWE-287): Authentication bypass vulnerabilities allow attackers to access protected resources without valid credentials.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (2)
Quick Facts
Related CVEs (CWE-287)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-33539 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts