Cyber Resilience

CVE-2021-41823

MediumPublic PoC

Published: 01 January 2023

Published
01 January 2023
Modified
11 April 2025
KEV Added
Patch
CVSS Score v3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0023 46.5th percentile
Risk Priority 12 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-41823 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Kemptechnologies Web Application Firewall. Its CVSS base score is 6.1 (Medium).

Operationally, ranked at the 46.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

The Web Application Firewall (WAF) in Kemp LoadMaster 7.2.54.1 allows certain uses of onmouseover to bypass an XSS protection mechanism.

CWE(s)

Related Threats

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

Affected Assets

kemptechnologies
web application firewall
7.2.54.1

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