What is privilege escalation?

Applications and systems are designed to accommodate multiple user accounts, providing distinct authoritative roles to perform specific actions. These actions are known as privileges. They encompass a variety of tasks, such as reading from or writing to files and executing commands with root permissions.

Privilege escalation is an unauthorized exploitation of privileges within a system or application. It occurs when a user gains a higher level of access or permission than originally assigned. It involves an attacker exploiting vulnerabilities or weaknesses in a system or application to gain elevated privileges. Once escalated, the attacker can perform malicious actions such as installing malware, modifying system configurations, or accessing sensitive data. These privileges may include administrative access, root access, or other elevated permissions beyond what the user should have.

Types of privilege escalation

There are two types of privilege escalation:

• Vertical privilege escalation

• Horizontal privilege escalation

Vulnerabilities leading to privilege escalation

Some of the vulnerabilities that lead to privilege escalation are given below:

• Security misconfigurations: These are insecure configuration settings, such as file permissions, allowing unauthorized users to read, write, or execute sensitive files that pose a significant risk. It includes misconfigured access controls, such as weak or default passwords, hardcoded credentials, and a lack of multifactor authentication, which can create vulnerabilities for privilege escalation.

• Insecure environment variables: If environment variables are not properly set, then an attacker can manipulate the variables, leading to the execution of malicious code with escalated privileges.

• Social engineering: An attacker manipulates an individual into revealing confidential information that compromises security, such as revealing passwords or granting unauthorized access to systems.

• Kernel exploits: Vulnerabilities in the OS kernel, such as buffer overflow and race conditions, can allow attackers to gain kernel-level privileges, effectively bypassing security mechanisms and gaining full control over the system. A buffer overflow allows attackers to manipulate program control flow and execute malicious code by overwriting the memory beyond allocated buffers. Attackers can manipulate timing to exploit conditions, potentially leading to unauthorized privilege escalation.

The visual representation of how privilege escalation impacts an application is given below:

Example

Suppose the system administrator has included . in the PATH variable to avoid adding ./every time to execute scripts from the current directory. This configuration creates a vulnerability, and allows an attacker to potentially escalate privileges on the system. If an attacker places a file named ls containing malicious code, and when an admin executes the ls command to list files, the malicious code within the file gets executed, posing a security threat.

Conclusion

Understanding how privilege escalation works is essential for implementing security measures within the systems, applications, and networks. Privilege escalation attacks pose risks to the security and integrity of critical systems and their sensitive data. It is imperative for organizations to prevent and detect privilege escalation attempts effectively by implementing protective measures, such as regular monitoring, least privilege access controls, and security audits.