Cyber Resilience

CVE-2021-43991

MediumPublic PoC

Published: 03 December 2021

Published
03 December 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 6.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N
EPSS Score 0.0028 52.0th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-43991 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Kentico Xperience. Its CVSS base score is 6.8 (Medium).

Operationally, ranked in the top 48.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

The Kentico Xperience CMS version 13.0 – 13.0.43 is vulnerable to a persistent Cross-Site Scripting (XSS) vulnerability (also known as Stored or Second-Order XSS). Persistent XSS vulnerabilities occur when the application stores and retrieves client supplied data without proper handling…

more

of dangerous content. This type of XSS vulnerability is exploited by submitting malicious script content to the application which is then retrieved and executed by other application users. The attacker could exploit this to conduct a range of attacks against users of the affected application such as session hijacking, account take over and accessing sensitive data.

CWE(s)

Related Threats

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

Affected Assets

kentico
xperience
13.0.0 — 13.0.43

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