Cyber Resilience

CVE-2025-3584

MediumPublic PoC

Published: 03 June 2025

Published
03 June 2025
Modified
05 June 2025
KEV Added
—
Patch
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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 0.0017 37.5th percentile
Risk Priority 10 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-3584 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Thenewsletterplugin Newsletter. Its CVSS base score is 4.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 37.5th 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 Newsletter WordPress plugin before 8.8.2 does not sanitise and escape some of its Subscription settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example…

more

in multisite setup).

CWE(s)
CWE-79

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
attack.mitre.org →
T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
attack.mitre.org →
T1555.003 Credentials from Web Browsers Credential Access
Adversaries may acquire credentials from web browsers by reading files specific to the target browser.
attack.mitre.org →
Why these techniques?

Stored XSS allows admins to inject JS payloads executed in other authenticated users' browsers on form interactions, enabling browser session hijacking (T1185), web session cookie theft (T1539), and credentials from web browsers (T1555.003).

Affected Assets

thenewsletterplugin
newsletter
≤ 8.8.2

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.

CA-8 Penetration Testing
addresses: CWE-79

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

SI-10 Information Input Validation
addresses: CWE-79

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

SI-15 Information Output Filtering
addresses: CWE-79

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

References