Cross Site Scripting Vulnerability in Flatpress CMS # FlatPress CMS Stored XSS in v1.3.1
**CVE-2025-25460**
**Author:** Athul S
## Description
A stored Cross-Site Scripting (XSS) vulnerability was identified in **FlatPress 1.3.1** within the "Add Entry" feature. This vulnerability allows **authenticated attackers** to inject malicious JavaScript payloads into blog posts, which execute when other users view the posts. The issue arises due to **improper input sanitization** of the **"TextArea" field** in the blog entry submission form.
## Attack Vectors
- An **authenticated attacker** can inject a malicious **JavaScript payload** into the blog post entry.
- The payload executes when an **admin or another user** visits the affected blog entry.
- This could lead to **session hijacking, phishing, or other client-side attacks**.
## Proof of Concept (PoC)
### Steps to Reproduce:
1. **Login as an Admin** in FlatPress v1.3.1.
2. Navigate to the **"Add Entry"** section.
3. Insert the following **XSS payload** in the text area:
```html
<script>alert('XSS Payload Triggered');</script>
```
4. Save the Entry and View the Post
The JavaScript payload will execute when the page loads, triggering an **XSS alert box**.





## Impact
- **Code Execution:** ✅ *(JavaScript execution in the victim's browser)*
- **Potential Exploits:**
- **Session Hijacking** (stealing admin cookies).
- **Phishing Attacks** (redirecting users to malicious sites).
- **Defacement** (injecting unwanted content into the page).
## Affected Product
- **Product:** FlatPress
- **Version:** 1.3.1
- **Component:** Add Entry Feature (TextArea Field)
## Mitigation
- **Sanitize user inputs** before rendering.
- **Implement Content Security Policy (CSP)** to block inline scripts.
- **Update to FlatPress 1.4-dev**, where the issue is patched.
## Vendor Contact
- Contacted via email:
- [hello@flatpress.org](mailto:hello@flatpress.org)
- [frank.pcn@gmail.com](mailto:frank.pcn@gmail.com)
- Vendor **confirmed** the issue on **January 12, 2025**.
- The vulnerability is being patched in the **FlatPress 1.4-dev branch**.
## References
- [FlatPress Official Website](https://www.flatpress.org/)
- [FlatPress GitHub Repository](https://github.com/flatpressblog/flatpress)
## Discoverer
**Athul S**
[4.0K] /data/pocs/c22e5a54f9b5b6aeb76f83406bdcb9224510cd7f
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