Cyber Resilience

CVE-2021-39340

MediumPublic PoC

Published: 01 November 2021

Published
01 November 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 4.8 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0069 72.3th percentile
Risk Priority 10 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-39340 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Bracketspace Notification. Its CVSS base score is 4.8 (Medium).

Operationally, ranked in the top 27.7% 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 Notification WordPress plugin is vulnerable to Stored Cross-Site Scripting due to insufficient input validation and sanitization via several parameters found in the ~/src/classes/Utils/Settings.php file which made it possible for attackers with administrative user access to inject arbitrary web scripts,…

more

in versions up to and including 7.2.4. This affects multi-site installations where unfiltered_html is disabled for administrators, and sites where unfiltered_html is disabled.

CWE(s)

Related Threats

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

Affected Assets

bracketspace
notification
≤ 7.2.4

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