CVEs-PoC/2021/CVE-2021-3739.md

### [CVE-2021-3739](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3739)
![](https://img.shields.io/static/v1?label=Product&message=kernel&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=%3D%20Fixed%20in%20v5.15-rc1%20and%20above.%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-476%20-%20NULL%20Pointer%20Dereference&color=brighgreen)

### Description

A NULL pointer dereference flaw was found in the btrfs_rm_device function in fs/btrfs/volumes.c in the Linux Kernel, where triggering the bug requires ‘CAP_SYS_ADMIN’. This flaw allows a local attacker to crash the system or leak kernel internal information. The highest threat from this vulnerability is to system availability.

### POC

#### Reference
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e4571b8c5e9ffa1e85c0c671995bd4dcc5c75091
- https://ubuntu.com/security/CVE-2021-3739

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