Blog2Social is a widely used WordPress plugin that enables automatic posting, cross-promoting, and scheduling of content across a variety of social networks. It’s particularly popular among content creators and marketing teams for its extensive integrations and automation features. However, in versions prior to 8.4.0, a critical Stored Cross-Site Scripting (XSS) vulnerability was discovered. This flaw allows users with the Contributor role to inject malicious scripts that get executed within the WordPress Dashboard, posing a significant security threat.
| CVE | CVE-2025-4133 |
| Blog2Social < 8.4.0 | |
| Critical | High |
| All Time | 4 165 020 |
| Active installations | 50 000+ |
| Publicly Published | May 2, 2025 |
| Last Updated | May 2, 2025 |
| Researcher | Krugov Artyom |
| OWASP TOP-10 | A7: Cross-Site Scripting (XSS) |
| PoC | Yes |
| Exploit | No |
| Reference | https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-4133 https://wpscan.com/vulnerability/ebd7e5f5-af8d-42ca-b6ff-af92e03d4a3e/ |
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| Logo of the plugin |  |
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Timeline
| April 28, 2025 | Plugin testing and vulnerability detection in the Blog2Social: Social Media Auto Post & Scheduler have been completed |
| April 28, 2025 | I contacted the author of the plugin and provided a vulnerability PoC with a description and recommendations for fixing |
| May 2, 2025 | Registered CVE-2025-4133 |
Discovery of the Vulnerability
he vulnerability was identified during routine security testing of the plugin’s post management and preview features. It was found that malicious input inserted into the Post Title field was not properly sanitized before being rendered within the Blog2Social “All Posts” admin view. This oversight enables stored XSS execution when an administrator or other user with sufficient privileges visits the affected admin panel section.
Understanding of XSS attack’s
Stored XSS, also known as persistent XSS, occurs when malicious scripts are permanently stored on the target server—commonly in a database—and are served to users when they access the infected content. In the WordPress ecosystem, this typically happens through unsanitized post titles, comments, or custom fields. For example, a Contributor inserting encoded JavaScript into a post title could trigger a script execution when viewed by an admin in the Dashboard, allowing session hijacking, credential theft, or arbitrary actions in the admin’s context.
Exploiting the XSS Vulnerability
To exploit CVE-2025-4133, the following steps must be taken:
POC:
1. Log in with a user account that has the Contributor role. 2. Create a new post and insert the following XSS payload into the post title field: "&gt;&lt;script&gt;&lt;/script&gt;&lt;img src=x onerror=alert(99917)&gt; 3. Submit the post for review. 4. Once an administrator navigates to Dashboard > Blog2Social > All Posts, the payload executes in their browser context.____
This execution can result in anything from an alert box (used in proof-of-concept) to full takeover scenarios using JavaScript-based session hijacking techniques.
Recommendations for Improved Security
To mitigate the risks posed by CVE-2025-4133, administrators should immediately update the Blog2Social plugin to version 8.4.0 or later, where the vulnerability has been patched. This update ensures that malicious payloads can no longer be executed via stored content in the admin dashboard.
Developers must ensure that all user inputs, especially in dynamic and customizable fields such as post titles or headers used in dashboard interfaces, are properly sanitized before saving and escaped before rendering. In particular, fields that are accessible to users with Contributor or lower-level roles should never allow unfiltered HTML or JavaScript input.
To prevent exploitation through browser script execution, implementing a Content Security Policy (CSP) is strongly recommended. A strict CSP can significantly reduce the risk of XSS by blocking inline scripts or external script execution from untrusted sources.
Administrators should also limit Contributor capabilities, ensuring they cannot inject potentially dangerous content into areas viewed by administrators. Where possible, use custom roles or plugins to fine-tune permission levels. Regular security audits and using a Web Application Firewall (WAF) can help detect and block such attacks before they are exploited. To prevent this type of attacks vendor used our methods of prevention.
By taking proactive measures to address Stored XSS vulnerabilities like CVE-2025-4133, WordPress website owners can enhance their security posture and safeguard against potential exploitation. Stay vigilant, stay secure.
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Artyom k.