cve/2019/CVE-2019-5603.md

### [CVE-2019-5603](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-5603)
![](https://img.shields.io/static/v1?label=Product&message=FreeBSD&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=Kernel%20improper%20update%20of%20reference%20count&color=brighgreen)

### Description

In FreeBSD 12.0-STABLE before r350261, 12.0-RELEASE before 12.0-RELEASE-p8, 11.3-STABLE before r350263, 11.3-RELEASE before 11.3-RELEASE-p1, and 11.2-RELEASE before 11.2-RELEASE-p12, system calls operating on file descriptors as part of mqueuefs did not properly release the reference allowing a malicious user to overflow the counter allowing access to files, directories, and sockets opened by processes owned by other users.

### POC

#### Reference
- http://packetstormsecurity.com/files/153752/FreeBSD-Security-Advisory-FreeBSD-SA-19-15.mqueuefs.html
- http://packetstormsecurity.com/files/154172/FreeBSD-Security-Advisory-FreeBSD-SA-19-24.mqueuefs.html

#### Github
- https://github.com/raymontag/CVE-2019-5603