How to script a privilege escalation attack simulation in Linux

Question

As part of security assessments, I want to script a privilege escalation attack simulation on Linux to test the effectiveness of security controls. My focus is on:

• Common privilege escalation techniques (kernel exploits, misconfigured SUID binaries, sudo misconfigurations).
• Writing an automated script to check for vulnerable configurations.
• Simulating real-world attack scenarios safely in a controlled environment.
  Any recommendations on ethical testing methodologies and tools that can assist in automating privilege escalation checks would be highly valuable.

Answer 1

Simulating a privilege escalation attack in Linux is a critical component of security assessments, enabling you to identify and rectify vulnerabilities before malicious actors can exploit them. Here's a structured approach to scripting such simulations:

1. Understand Common Privilege Escalation Techniques

Familiarize yourself with prevalent methods attackers use to gain elevated privileges:

• Kernel Exploits: Attackers exploit vulnerabilities within the Linux kernel to execute arbitrary code with root privileges. Regularly updating the kernel and applying patches can mitigate this risk.

• Misconfigured SUID Binaries: Set User ID (SUID) binaries run with the file owner's privileges, often root. Misconfigurations can allow users to execute these binaries with elevated rights.

• Sudo Misconfigurations: Improper sudo settings can grant users unintended root access. For instance, allowing a user to run commands without proper restrictions can be exploited.

2. Develop an Automated Vulnerability Assessment Script

Creating a script to detect potential vulnerabilities involves:

• Environment Setup: Use a controlled environment, such as a virtual machine or container, to prevent unintended system damage.

• SUID Binaries Enumeration: Identify all SUID binaries and assess them for potential exploitation.

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

• Sudo Permissions Audit: Review users' sudo privileges to spot misconfigurations.

sudo -l

• Kernel Version Check: Compare the system's kernel version against known vulnerabilities.

uname -r

• Automation: Incorporate these checks into a script that logs findings for review.

3. Simulate Real-World Attack Scenarios Safely

To emulate potential attacks without compromising system integrity:

• Controlled Exploitation: Use proof-of-concept exploits in a non-production environment to understand their impact.

• Monitoring and Logging: Track all actions during simulations to analyze system responses and refine security measures.

4. Ethical Testing Methodologies and Tools

Adhere to ethical guidelines to ensure responsible testing:

• Obtain Authorization: Secure explicit permission before conducting any tests, especially on production systems.

• Use Established Tools: Leverage reputable tools designed for security assessments.

  • LinPEAS: Scans for potential privilege escalation paths.

  • Linux Exploit Suggester: Identifies possible exploits based on system configurations.

• Non-Destructive Testing: Avoid tests that could disrupt system operations or compromise data integrity.

Example Use Case

Suppose you're assessing a server running an outdated kernel version.

1. Kernel Version Identification: Determine the kernel version.

   uname -r

2. Vulnerability Research: Check if this version has known vulnerabilities.

3. Exploit Testing in a Safe Environment: If a vulnerability exists, test a related exploit in a virtual machine replicating the server's environment.

4. Mitigation Implementation: Apply necessary patches or updates to address the vulnerability.

By following this structured approach, you can effectively script and execute privilege escalation attack simulations, enhancing your system's security posture while adhering to ethical standards.