Privilege escalation

Introduction:

Privilege escalation is a critical step in penetration testing that involves the process of gaining elevated permissions to access restricted resources on a target system. It is one of the most crucial steps for attackers and pen testers to gain full control over the target system. In this blog, we will discuss privilege escalation techniques, tools, and tricks used in pen testing.

Privilege Escalation Techniques:

1. Exploiting Weak Service Configurations:

One of the most common privilege escalation techniques is exploiting weak service configurations. This involves identifying misconfigured services running on the target system and using them to gain elevated privileges. For example, a pen tester could exploit a service running with SYSTEM-level privileges that is not properly protected. The following steps can be used to exploit a weak service configuration:

- Identify the service running on the target system using tools like Task Manager or Process Explorer.
- Find the service executable path using the command "sc qc <service name>" or "sc queryex <service name>".
- Check the permissions on the service executable and its parent directory using the command "icacls <executable path>". If the service executable or its parent directory has weak permissions, a pen tester could replace it with a malicious executable that executes with elevated privileges.

2. Exploiting Weak File Permissions:

Another common technique is exploiting weak file permissions. A pen tester could identify a file that is writable by a low-privileged user but executable by a high-privileged user, allowing them to run code as the high-privileged user. The following steps can be used to exploit weak file permissions:

- Identify files with weak permissions using tools like AccessChk or icacls.
- Create a malicious executable or script that can be executed by the high-privileged user.
- Write the malicious code to the file with weak permissions and execute it as the high-privileged user.

3. Exploiting Weak User Permissions:

A pen tester could exploit weak user permissions by escalating privileges from a low-privileged user to a high-privileged user, allowing them to access sensitive resources on the target system. The following steps can be used to exploit weak user permissions:

- Identify low-privileged users on the target system using tools like net user or whoami.
- Identify high-privileged users on the target system using tools like net group or net localgroup.
- Find a vulnerability in the low-privileged user's account that can be exploited to escalate privileges. This could be a password weakness or a misconfiguration in the user's permissions.
- Exploit the vulnerability to gain access to the high-privileged user's account.

4. Exploiting Vulnerabilities:

A pen tester could exploit known or unknown vulnerabilities in the target system to gain elevated privileges. This could be achieved by using exploits or custom scripts. The following steps can be used to exploit vulnerabilities:

- Identify vulnerabilities in the target system using tools like Nmap or Nessus.
- Write a custom exploit or use a pre-built exploit to target the vulnerability.
- Run the exploit to gain elevated privileges.

Privilege Escalation Tools:

1. Metasploit:

Metasploit is a popular framework used for pen testing that includes a wide range of privilege escalation modules. It provides a graphical user interface (GUI) and a command-line interface (CLI) for pen testers to use. The following steps can be used to use Metasploit for privilege escalation:

- Identify the target system using tools like Nmap or Nessus.
- Use the "search" command in Metasploit to find privilege escalation modules for the target system.
- Select a suitable module and run it to gain elevated privileges.

2. PowerUp:

PowerUp is a PowerShell module used for privilege escalation. It includes a wide range of functions to identify and exploit vulnerabilities in the target system. The following steps can be used to use PowerUp for privilege escalation:

- Download and import the PowerUp module into PowerShell.
- Use the "Invoke-AllChecks" function to identify vulnerabilities in the target system.
- Use the "Invoke-PrivescCheck" function to identify privilege escalation opportunities.
- Use the "Invoke-AllChecks" function to execute the privilege escalation exploits.

3. BloodHound:

BloodHound is a tool used for privilege escalation in Active Directory environments. It identifies privilege escalation paths and vulnerabilities in the target system. The following steps can be used to use BloodHound for privilege escalation:

- Gather data from the target system using tools like Powerview or AD Recon.
- Import the data into BloodHound using the "Import-AdRecon" or "Import-PowerviewCsv" function.
- Use the "Find-PathsToDomainAdmin" function to identify privilege escalation paths.
- Use the "Invoke-SharpHound" function to execute privilege escalation exploits.

Helpful Tricks:

1. Always escalate privileges to the highest level possible:

When exploiting vulnerabilities or weaknesses, always aim to escalate privileges to the highest level possible. This will give you full control over the target system and access to all the resources.

2. Use stealth techniques:

To avoid detection, use stealth techniques when executing privilege escalation exploits. This could include using anti-virus evasion techniques or disguising malicious files as legitimate files.

3. Clean up after yourself:

Always clean up after yourself to avoid leaving any traces of your activity on the target system. This could include removing any backdoors or deleting any files used during the privilege escalation process.

Conclusion:

Privilege escalation is a critical step in pen testing that involves gaining elevated permissions to access restricted resources on a target system. There are various techniques, tools, and tricks that can be used to achieve this, including exploiting weak service configurations, file permissions, user permissions, and vulnerabilities. Tools like Metasploit, PowerUp, and BloodHound can be used to automate the privilege escalation process. Remember to always aim for the highest level of privilege possible, use stealth techniques to avoid detection, and clean up after yourself to avoid leaving any traces of your activity.

n0600d