Privilege escalation is obtaining access to resources or privileges restricted to a specific group or level of users within an organization. This can be accomplished through various methods, including exploiting vulnerabilities within the system or network, utilizing social engineering techniques to deceive users into providing their login credentials or access, or taking advantage of incorrectly configured access controls to obtain unauthorized access to restricted resources.

How Do These Types of Attacks Occur?

Consider a scenario in which a malicious individual desires access to a restricted section of a company’s network. They may employ various tactics to achieve this goal, such as exploiting a network firewall vulnerability to evade security controls and gain entry to the restricted area. Alternatively, they could utilize social engineering methods, like impersonating a trustworthy colleague or an IT department representative, to deceive an employee into providing their login credentials. Once inside the restricted area, the attacker may attempt to elevate their privileges further by exploiting system vulnerabilities or manipulating access control configurations, which could allow them to access confidential information, alter system settings, or disrupt the company’s operations. The primary objective of a privilege escalation attack is to obtain higher privileges within the system or network, such as an administrator or root access. This enables the attacker to dominate the system and resources and potentially inflict substantial damage or disruption.

Privilege Escalation Types

Various types of privilege escalation exist, each of which possesses distinct characteristics and exploitation methods. These include:

  • Vertical privilege escalation involves a user attempting to acquire access to resources or privileges above their current level. For example, a low-level employee may attempt to enter the server room or administrative accounts.
  • Horizontal privilege escalation is when a user tries to obtain access to resources or privileges on the same level as their own but in a different context. For instance, an employee may attempt to access a coworker’s account or files.
  • Lateral privilege escalation occurs when a user tries to access resources or privileges on the same level as their own but in a different system or network. For example, an employee may attempt to access another department’s network or servers.
  • Temporary privilege escalation involves temporarily gaining higher privileges, often through a “backdoor” or other means of bypassing security controls. These privileges are typically only granted for a specific task or time and are subsequently revoked.

Each method uniquely affects users, accounts, workstations, and networks.

Vertical Privilege Escalation

To perform privilege escalation at this level, the attacker must first gain access to a user account and then leverage this access to gain access to other systems or resources. The attacker must possess the necessary credentials for each system accessed, including passwords or keys. Physical access to a computer or network device may also be necessary for the attacker to escalate their privileges.

An example of vertical privilege escalation could involve an employee who has access to their account and the resources granted at that level of access but then attempts to gain access to resources or privileges above their own. For example, an employee who typically accesses specific reports may attempt to access the company’s financial records or the server room. This type of privilege escalation involves the user attempting to move “up” the hierarchy of privileges, hence the term “vertical” escalation.

Horizontal Privilege Escalation

When an attacker gains access to a system-level account, such as an administrator account, they can escalate their privileges to access additional resources or privileges intended only for a group of highly privileged administrators. This can result in the attacker having complete control of the system and its resources, potentially causing significant damage or disruption. In the case of horizontal privilege escalation, an employee with access to their account and the resources typically granted to that level of access may try to access resources or privileges that are on the same level as their own but in a different context.

For example, an employee may attempt to access a coworker’s account and files or resources intended for use by another department or group within the organization. This type of privilege escalation involves the user moving laterally within the same level of privileges, thus the term “horizontal” escalation.  

Lateral Privilege Escalation

Lateral privilege escalation occurs when a user tries to access resources or privileges on the same level as their own but in a different system or network. This type of escalation can be particularly dangerous because it allows the user to move laterally within the same privileges, potentially bypassing security controls and gaining access to sensitive data or resources.

For instance, an employee with access to their account and the resources typically granted to that level of access but attempts to gain access to resources or privileges that are on the same level as their own but in a different system or network can be an example of lateral privilege escalation. The employee may try to access another department’s network, and servers or access resources only intended for use by another group or organization. This type of privilege escalation involves the user attempting to move laterally from one system or network to another, which can pose a significant threat to the security of the organization’s data and resources.

Temporary Privilege Escalation

Temporarily granting users higher privileges may be necessary for certain situations, known as temporary privilege escalation. This is typically done by bypassing security controls or a “backdoor” for a specific task or period and then revoked once completed. While temporary privilege escalation can be helpful for system maintenance and accessing restricted resources, organizations must carefully manage and monitor their use to prevent unauthorized access or data breaches by attackers.

A system administrator may require temporary access to sensitive files or systems to perform maintenance tasks. The administrator’s privileges are elevated to complete the required task, but these elevated privileges must be removed once the task is done. This type of privilege escalation can be helpful for users who need temporary access to resources that are typically restricted. However, it is essential to carefully monitor and control temporary privileges to prevent unauthorized access or exploitation by attackers.

Is Privilege Escalation a Security Problem?

Privilege escalation is a critical security challenge for organizations, as it involves exploiting system vulnerabilities to gain access to resources and privileges not typically available to users. Attackers may use privilege escalation to access sensitive data or perform otherwise restricted actions. These attacks can be dangerous, allowing attackers to bypass security controls and gain access to resources they should not have. Successful privilege escalation attacks can result in security breaches, data loss, and severe consequences for the organization and its clients. Thus, organizations must understand the risks of privilege escalation and implement appropriate security measures to prevent them.

Privilege Escalation Prevention

Preventing privilege escalation is crucial to maintain the security of an organization’s systems and resources. Here are several ways to mitigate the risk of a security breach:

  • Implementing strong password policies and regular password changes to prevent unauthorized access to accounts.
  • Following the principle of least privilege by granting users only the necessary access and privileges for their job roles.
  • Regularly reviewing and updating access controls to prevent unauthorized resource access.
  • Using security tools, including firewalls and intrusion detection systems, to prevent unauthorized access and detect potential security threats.
  • Using encrypted communication channels, like SSL or TLS, to secure sensitive data during transit.
  • Implementing two-factor authentication to add an extra layer of security.
  • Conducting regular security assessments to identify and fix vulnerabilities in the system.
  • Monitoring systems for unusual activities and alerting to suspicious activities.
  • Regularly patching and updating systems to fix known vulnerabilities.

Least privilege for Administrator Accounts

The principle of least privilege dictates that administrator accounts should only be granted access to resources and privileges essential for their duties.

For instance, if an administrator is responsible for managing user accounts and access controls, they should only have access to the necessary resources and tools for performing those tasks. Other resources or privileges not essential to their job should be restricted.

Permission Levels: Default Deny, Default Allow

Permission levels are critical in defining the access and privileges granted to users or processes within a system or network. Two widely used approaches for setting permission levels are default deny and default allow. Default denial is a security measure that restricts access to all resources and privileges by default unless explicitly authorized. Conversely, default allows grants access to all resources and privileges by default unless explicitly denied. Both approaches have advantages and disadvantages, and organizations should consider their specific needs and objectives carefully before selecting the appropriate method.

Conclusion

In conclusion, privilege escalation is a significant concern in cybersecurity, as attackers can exploit system vulnerabilities to gain unauthorized access to resources and privileges. Organizations can protect their systems and valuable data by understanding the different types of privilege escalation and implementing appropriate security measures.