How severe is CVE-2021-33536?

CVE-2021-33536 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-33536 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33536?

CVE-2021-33536 primarily affects Weidmueller Ie-wl-bl-ap-cl-eu Firmware. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-33536?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-33536 published?

CVE-2021-33536 was published on 2021-06-25 and last updated on 2026-06-17.

CVE-2021-33536

CVE-2021-33536 is a high-severity vulnerability in Weidmueller Ie-wl-bl-ap-cl-eu Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-191.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (60th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-191
Affected product: Weidmueller Ie-wl-bl-ap-cl-eu Firmware
Published: 2021-06-25
Last modified: 2026-06-17

Description

In Weidmueller Industrial WLAN devices in multiple versions an exploitable denial-of-service vulnerability exists in ServiceAgent functionality. A specially crafted packet can cause an integer underflow, triggering a large memcpy that will access unmapped or out-of-bounds memory. An attacker can send this packet while unauthenticated to trigger this vulnerability.

Frequently asked questions

What is CVE-2021-33536?: In Weidmueller Industrial WLAN devices in multiple versions an exploitable denial-of-service vulnerability exists in ServiceAgent functionality. A specially crafted packet can cause an integer underflow, triggering a large memcpy that will access unmapped or out-of-bounds memory. An attacker can send this packet while unauthenticated to trigger this vulnerability.
How severe is CVE-2021-33536?: CVE-2021-33536 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-33536 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33536?: CVE-2021-33536 primarily affects Weidmueller Ie-wl-bl-ap-cl-eu Firmware. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-33536?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-33536 published?: CVE-2021-33536 was published on 2021-06-25 and last updated on 2026-06-17.

References

https://cert.vde.com/en-us/advisories/vde-2021-026

Affected products (8)

cpe:2.3:o:weidmueller:ie-wl-bl-ap-cl-eu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:weidmueller:ie-wlt-bl-ap-cl-eu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:weidmueller:ie-wl-bl-ap-cl-us_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:weidmueller:ie-wlt-bl-ap-cl-us_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:weidmueller:ie-wl-vl-ap-br-cl-eu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:weidmueller:ie-wlt-vl-ap-br-cl-eu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:weidmueller:ie-wl-vl-ap-br-cl-us_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:weidmueller:ie-wlt-vl-ap-br-cl-us_firmware:*:*:*:*:*:*:*:*

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