CVE-2025-23459
Published: 26 March 2025
Summary
CVE-2025-23459 is a high-severity Cross-site Scripting (CWE-79) vulnerability. Its CVSS base score is 7.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 40.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-15 (Information Output Filtering).
Deeper analysis
CVE-2025-23459 is an Improper Neutralization of Input During Web Page Generation vulnerability, classified as Reflected Cross-site Scripting (XSS) under CWE-79, affecting the NsThemes NS Simple Intro Loader (ns-simple-intro-loader) WordPress plugin. This issue impacts all versions from n/a through 2.2.3. The vulnerability has a CVSS v3.1 base score of 7.1 (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L), indicating high severity due to network accessibility, low attack complexity, no required privileges, user interaction, and changed scope.
Remote attackers without authentication can exploit this vulnerability by crafting malicious input that is reflected in dynamically generated web pages, tricking users into interacting with it, such as clicking a malicious link. Successful exploitation allows script execution in the context of the victim's browser, potentially leading to low-impact confidentiality breaches (e.g., session token theft), integrity modifications (e.g., page alterations), and availability disruptions, amplified by the cross-origin scope change.
The Patchstack advisory at https://patchstack.com/database/Wordpress/Plugin/ns-simple-intro-loader/vulnerability/wordpress-ns-simple-intro-loader-plugin-2-2-3-reflected-cross-site-scripting-xss-vulnerability?_s_id=cve provides details on this Reflected XSS vulnerability in NS Simple Intro Loader version 2.2.3. Security practitioners should consult this reference for specific mitigation guidance, such as plugin updates if available.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-8199
Vulnerability details
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in NsThemes NS Simple Intro Loader ns-simple-intro-loader allows Reflected XSS.This issue affects NS Simple Intro Loader: from n/a through <= 2.2.3.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The reflected XSS vulnerability in a public-facing WordPress plugin directly enables exploitation of public-facing applications to achieve initial access or client-side impacts such as session token theft.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
SI-10 mandates validation of information inputs, directly preventing the improper neutralization of malicious input that enables reflected XSS in CVE-2025-23459.
SI-15 requires filtering of information outputs, comprehensively addressing the reflection of unneutralized input during web page generation exploited in this WordPress plugin XSS vulnerability.
SI-2 ensures timely flaw remediation, such as updating the vulnerable NS Simple Intro Loader plugin to eliminate the reflected XSS issue.