CVE-2025-49032 in Gutenberg Blocks Plugin
Summary
by MITRE • 07/03/2025
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in PublishPress Gutenberg Blocks allows Stored XSS.This issue affects Gutenberg Blocks: from n/a through 3.3.1.
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Analysis
by VulDB Data Team • 07/03/2025
The vulnerability identified as CVE-2025-49032 represents a critical cross-site scripting flaw within the PublishPress Gutenberg Blocks plugin, specifically impacting versions ranging from the initial release through 3.3.1. This weakness falls under the well-established CWE-79 category of Cross-Site Scripting, which occurs when web applications fail to properly sanitize user input before incorporating it into dynamically generated web pages. The vulnerability enables attackers to inject malicious scripts that execute in the context of other users' browsers, creating a persistent threat vector that can affect multiple victims within the same web application environment.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization mechanisms within the Gutenberg Blocks plugin's web page generation process. When users create or modify content through the Gutenberg editor interface, the plugin fails to adequately neutralize potentially malicious input that could contain script tags or other harmful code sequences. This improper handling occurs during the rendering phase where user-provided content is directly embedded into HTML output without sufficient security measures such as HTML escaping or content validation. The stored nature of this XSS vulnerability means that malicious scripts are permanently saved within the application's database or storage system, making them persistent and automatically executed whenever affected pages are loaded by other users.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, data exfiltration, and redirection to malicious websites. Attackers can craft malicious payloads that exploit the stored XSS to steal cookies, modify page content, or even execute arbitrary code within the victim's browser context. The vulnerability affects all users who interact with the Gutenberg Blocks functionality, potentially compromising the entire WordPress site if administrators or editors are targeted. Given that Gutenberg Blocks is widely used for content management, the attack surface for exploitation is substantial, particularly in environments where multiple users have editing privileges.
Mitigation strategies for this vulnerability should prioritize immediate patching of the affected plugin to version 3.3.2 or later, which contains the necessary security fixes. System administrators should implement comprehensive input validation at multiple layers including client-side and server-side sanitization to prevent malicious code injection. The implementation of Content Security Policy headers can provide additional protection against script execution, while regular security audits and penetration testing should be conducted to identify similar vulnerabilities in other plugins or themes. Organizations should also consider implementing web application firewalls and monitoring systems to detect and block suspicious input patterns. This vulnerability aligns with ATT&CK technique T1566.001 for initial access through malicious content and T1059.001 for command and scripting interpreter, highlighting the multi-stage nature of exploitation that can occur through such XSS vulnerabilities.