How to Execute Privilege Escalation on Modern Operating Systems

November 27, 20235 min read

Privilege escalation refers to the technique by which an attacker obtains a higher level of permissions on a system than what was originally granted. On modern operating systems (OS), this often involves transitioning from a standard user to a user with administrative rights. It is an important step in a cyber attack, as it allows for full control over the system. Exploiting privilege escalation requires understanding OS vulnerabilities, misconfigurations, or the exploitation of legitimate system functionality.

Disclaimer: The following information is for educational purposes only. Unauthorized access and manipulation of computer systems is illegal and unethical. Always have explicit permission before attempting any testing or security assessment on systems that do not belong to you.

Understanding the Environment

  • Identify the OS version: Before any attempt, you must know the exact OS you are dealing with (e.g., Windows 10, macOS Big Sur, Ubuntu 20.04).
  • Gather system information: Tools like uname -a on Linux or systeminfo on Windows can give you detailed system information.
  • Understand the patch level: Knowing if the system is up-to-date with patches can help identify known vulnerabilities.

Local vs. Remote Escalation

  • Local Escalation: This involves gaining elevated privileges on a system you already have access to. Often performed after gaining a foothold via another vulnerability.
  • Remote Escalation: Involved gaining elevated privileges from a remote location, typically through network-based vulnerabilities.

Common Techniques

  1. Exploiting Known Vulnerabilities
    • Check vulnerabilities databases: Databases like CVE (Common Vulnerabilities and Exposures) can provide information about known vulnerabilities that may allow privilege escalation.
    • Security updates: Operating systems without recent security updates may be vulnerable to escalation attacks.
  2. Misconfigurations
    • Insecure permissions: Files and directories with overly permissive rights can allow standard users to modify or execute files leading to escalation.
    • Service misconfigurations: Services running with high privileges could be misconfigured to execute arbitrary code.
  3. Password Attacks
    • Cracking passwords: Weak passwords can be brute-forced or cracked using tools like John the Ripper or hashcat.
    • Pass-the-hash: Windows systems are susceptible to pass-the-hash attacks where an attacker reuses a valid password hash to gain unauthorized access.
  4. Privilege Escalation Scripts and Tools
    • For Linux: linpeas, beeswarm, and linux-exploit-suggester are tools that automate the search for potential privilege escalation vulnerabilities.
    • For Windows: windows-exploit-suggester, PowerSploit, and WinPEAS are some popular tools that serve a similar purpose.
  5. Kernel Exploits
    • Exploiting unpatched kernels: Older versions of kernels may have unpatched vulnerabilities that can be exploited using pre-built exploits or by compiling custom exploit code.
  6. Application Flaws
    • 3rd-party applications: Applications with known vulnerabilities or those running with higher privileges can be exploited to achieve privilege escalation.
  7. Social Engineering
    • Phishing: Convincing an administrator or user with elevated privileges to execute malicious code on their behalf.

Execution Steps

  • Preparation
    • Assess the system’s security.
    • Identify the target’s behavior.
    • Gather necessary tools.
  • Information Gathering
    • Enumerate users and permissions.
    • Look for running services and scheduled tasks.
    • Identify installed software.
  • Exploiting
    • Select and tailor the exploit based on gathered information.
    • Exploit vulnerable service, application, or OS feature.
  • Maintaining Access
    • Establish a backdoor or covert channel to ensure continued access.
  • Covering Tracks
    • Clear logs or use stealthy techniques to remain undetected.

Ethical Considerations and Legal Issues

  • Permission: Only perform privilege escalation on systems you have explicit authorization to test.
  • Disclosure: If you find a new vulnerability, report it to the software vendor responsibly.
  • Law and Regulations: Be aware of local and international laws concerning cyber security, data privacy, and computer crimes.

This overview is a condensed guide to the vast field of privilege escalation. Security professionals continually research these topics to protect systems from these types of attacks, and attackers evolve their methods in response. It’s a constantly shifting landscape that requires continuous study and ethical behavior.