Cyber Resilience

CVE-2021-20994

High

Published: 13 May 2021

Published
13 May 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0039 60.5th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-20994 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Wago 0852-0303 Firmware. Its CVSS base score is 8.8 (High).

Operationally, ranked in the top 39.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

In multiple managed switches by WAGO in different versions an attacker may trick a legitimate user to click a link to inject possible malicious code into the Web-Based Management.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

wago
0852-0303 firmware
≤ 1.2.3.s0
wago
0852-1305 firmware
≤ 1.1.7.s0
wago
0852-1505 firmware
≤ 1.1.6.s0
wago
0852-1305\/000-001 firmware
≤ 1.0.4.s0
wago
0852-1505\/000-001 firmware
≤ 1.0.4.s0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References