CVE-2021-4034 PoC — polkit 缓冲区错误漏洞

Source

https://github.com/Al1ex/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。

Description

Local Privilege Escalation in polkit's pkexec (CVE-2021-4034)

Readme

### Information

```
Exploit Title: Local Privilege Escalation in polkit's pkexec (CVE-2021-4034)
Date: 01/25/2022
Exploit Author: Qualys Research Team
Tested on: ubuntu 20.04.1 LTS
CVE ID: CVE-2021-27928
```

## How to Exploit
Test Environment：

![img](img/env.png)

Step 1：build the exp(From https://github.com/berdav/CVE-2021-4034)

```
make
```

![img](img/build.png)

Step 2：run exploit and get a root shell

![img](img/root.png)

### Analysis Detail

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

### Reference

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

https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt

### Disclosure Timeline

- 2021-11-18: Advisory sent to secalert@redhat.
- 2022-01-11: Advisory and patch sent to distros@openwall.
- 2022-01-25: Coordinated Release Date (5:00 PM UTC).

File Snapshot


 [4.0K]  /data/pocs/bf51e9949abc91ea6e8fa111bf9bc68eb49f58ae
├── [ 274]  cve-2021-4034.c
├── [4.0K]  img
│   ├── [161K]  build.png
│   ├── [167K]  env.png
│   └── [ 70K]  root.png
├── [ 400]  Makefile
├── [ 266]  pwnkit.c
└── [ 924]  README.md

1 directory, 7 files

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