CVE-2025-22281 in Simplish Plugin
Summary
by MITRE • 04/04/2025
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in joshix Simplish allows Stored XSS.This issue affects Simplish: from n/a through 2.6.4.
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Analysis
by VulDB Data Team • 04/04/2025
This vulnerability represents a critical cross-site scripting flaw in the joshix Simplish web application framework that enables attackers to execute malicious scripts in the context of other users' browsers. The vulnerability manifests as improper input neutralization during web page generation, specifically allowing stored cross-site scripting attacks that persist across user sessions. The flaw exists within the application's handling of user-supplied data that is subsequently rendered in web pages without adequate sanitization or encoding mechanisms.
The technical implementation of this vulnerability stems from insufficient validation and sanitization of input parameters that are stored and later retrieved for display in web interfaces. When users submit content through various application forms or interfaces, the system fails to properly encode or escape special characters that could be interpreted as executable script code. This stored data remains in the application's database or storage mechanisms and gets rendered in subsequent page generations without proper security context handling. The vulnerability affects all versions of Simplish from the initial release through version 2.6.4, indicating a long-standing issue that has not been adequately addressed in the codebase.
The operational impact of this vulnerability is severe as it provides attackers with persistent access to victim users' sessions and browser environments. Successful exploitation allows threat actors to steal session cookies, perform unauthorized actions on behalf of users, redirect victims to malicious sites, or extract sensitive information from the targeted application. The stored nature of this XSS vulnerability means that once an attacker successfully injects malicious code, it will affect all users who view the affected pages until the malicious content is removed from the application's storage. This persistent nature makes the vulnerability particularly dangerous for applications that handle sensitive user data or provide administrative functionality.
Security professionals should implement multiple layers of defense to mitigate this vulnerability. Input validation and sanitization must be strengthened at all entry points where user data is accepted and stored, with proper encoding of special characters before storage. The application should implement Content Security Policy headers to limit script execution capabilities and prevent unauthorized code injection. Additionally, output encoding should be applied consistently whenever user-supplied data is rendered in web pages, ensuring that any potentially malicious content is treated as data rather than executable code. This vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and follows ATT&CK technique T1531 which covers "Modify System Image" through code injection methods. Organizations should also consider implementing Web Application Firewalls and regular security scanning to detect and prevent exploitation attempts.