cve/2021/CVE-2021-25833.md

### [CVE-2021-25833](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-25833)
![](https://img.shields.io/static/v1?label=Product&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brightgreen)

### Description

A file extension handling issue was found in [server] module of ONLYOFFICE DocumentServer v4.2.0.71-v5.6.0.21. The file extension is controlled by an attacker through the request data and leads to arbitrary file overwriting. Using this vulnerability, a remote attacker can obtain remote code execution on DocumentServer.

### POC

#### Reference
- https://github.com/merrychap/poc_exploits/tree/master/ONLYOFFICE/CVE-2021-25833

#### Github
- https://github.com/konatabrk/POC-onlyoffice
- https://github.com/merrychap/POC-onlyoffice