cve/2021/CVE-2021-21787.md

### [CVE-2021-21787](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21787)
![](https://img.shields.io/static/v1?label=Product&message=Iobit&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-782%3A%20Exposed%20IOCTL%20with%20Insufficient%20Access%20Control&color=brighgreen)

### Description

A privilege escalation vulnerability exists in the way IOBit Advanced SystemCare Ultimate 14.2.0.220 driver handles Privileged I/O write requests. During IOCTL 0x9c40a0d8, the first dword passed in the input buffer is the device port to write to and the byte at offset 4 is the value to write via the OUT instruction. The OUT instruction can write one byte to the given I/O device port, potentially leading to escalated privileges of unprivileged users.

### POC

#### Reference
- https://talosintelligence.com/vulnerability_reports/TALOS-2021-1254

#### Github
No PoCs found on GitHub currently.