What Is Privilege Escalation?

Privilege escalation is a frequently exploited threat vector cyber attackers use to gain unauthorized access to an organization’s systems and resources. It is a complex network attack that enables attackers to gain illicit access to a target environment, persist and deepen their access with higher privileges, and carry out more severe activities like breaching confidential data, viewing private information, or installing malicious programs such as viruses.

Privilege escalation is when a threat actor gains elevated access and administrative rights to a system by exploiting security vulnerabilities. By modifying identity permissions to grant it increased rights and admin capabilities, privilege escalation enables attackers to conduct malicious activities with higher privilege levels, potentially resulting in significant damages.

Computer systems have different levels of privileges, ranging from standard users with limited permissions to administrators with complete control over the system. A successful privilege escalation incident means that an attacker has managed to escalate their own privilege level, thereby gaining increased control.

In turn, cyber attackers can use privilege escalation to open up new attack vectors on a target system, evolving the threat level from simple malware infections to catastrophic data breaches and network intrusions.

There are two primary types of privilege escalation attacks that threat actors use: vertical and horizontal. While both types involve attackers attempting to gain unauthorized access to resources or perform malicious actions, how the attack is carried out can involve different approaches.

Vertical Privilege Escalation

An attacker can use vertical privilege escalation to gain access from a standard user account to higher-level privileges, such as superuser or administrator, thereby granting them unrestricted control over the entire system. Oftentimes, this gives them full control over the system, allowing them to modify configurations, install software, create new user accounts with escalated privileges, or even delete essential data.

Horizontal Privilege Escalation

Horizontal privilege escalation occurs when an attacker gains access at the same permission level but under different user identities. For example, an attacker using an employee’s credentials through credential theft or phishing attempts is horizontal privilege escalation. The goal here isn’t necessarily gaining root privileges but accessing sensitive information belonging to other users within their own privilege level.

The key difference between these two forms of attack lies in what kind of access the attacker seeks: vertical involves taking advantage of vulnerabilities for elevated permissions, while horizontal exploits weak security practices among peers at similar permission levels.

Detecting both types require vigilance and robust cybersecurity measures, including security monitoring systems for unusual activity and implementing robust authentication methods. Organizations must be aware of the mechanisms behind these assaults and how they’re carried out to ensure they are adequately shielded from potential threats.

Attackers can gain initial penetration into a system by finding weak points in an organization’s cybersecurity framework. Once the initial infiltration is successful, threat actors leverage specific strategies that hinge on either vertical or horizontal techniques:

• Vertical: Attackers exploit vulnerabilities within the system or software applications to escalate their privileges from a standard user account level up to privileged user levels, such as those held by system administrators. In vertical privilege escalation attacks, threat actors may also use social engineering techniques like phishing emails to trick users into granting access inadvertently or revealing sensitive information that aids in credential theft.
• Horizontal: Unlike vertical privilege escalation, which involves elevating permissions to gain root or administrator privileges, horizontal privilege escalation focuses on lateral movement across peer-level accounts. Cybercriminals often use tactics like credential theft and session hijacking during these attacks. They may even inject a malicious payload into software applications that users with similar permission levels frequently use.

Whether conducted vertically or horizontally, privilege escalation commonly works by exploiting misconfiguration in networks and systems. This includes tapping into vulnerabilities like failure to configure authentication for sensitive systems, administrative mistakes in firewall configuration, or specific design flaws or oversights in operating systems or web applications.

Privilege escalation attacks can also be carried out locally or remotely. Local privilege escalation attacks commonly begin on-premises, typically by someone inside the organization. Remote escalation, which is increasingly more pervasive, can start from almost anywhere.

Privilege escalation attacks can be better prevented using a strategic combination of sound cybersecurity practices and tools. Organizations should ensure that their implemented security measures are robust and regularly updated to prevent these types of cyberattacks.

Remember, no single method will catch every possible attack vector. Organizations need to have robust defenses and proactive detection measures in place that leverage a combination of strategies to mitigate such threats.

In cybersecurity, privilege escalation is a technique where an attacker compromises a system to gain unauthorized access and escalate privileges. This malicious activity can occur through various attack vectors, such as credential exploitation, vulnerabilities and exploits, misconfigurations, malware, or social engineering.

Malware

Attackers often use malware payloads to attempt privilege elevation on targeted systems. This type of attack typically starts with gaining basic level access before deploying the malicious payload that escalates their authority within the system.

Credential Exploitation

An attacker often attempts privilege escalation by taking advantage of weak user accounts or performing credential theft. Once they have gained access to these credentials, they can perform malicious actions under the guise of a privileged user.

Vulnerabilities and Exploits

A common method used in Linux and Windows privilege escalation involves exploiting software vulnerabilities. For instance, if an application doesn’t adhere to the least-privilege principle, it may allow for vertical privilege escalation where an attacker gains root or administrator privileges.

Misconfigurations

Sometimes system administrators inadvertently create opportunities for horizontal privilege escalation due to misconfiguration errors. These could include granting sudo access unnecessarily or not properly securing privileged account information.

Social Engineering

This method relies heavily on human interaction rather than technical flaws. A typical scenario might involve tricking employees into revealing their login details, allowing attackers easy entry into secure networks from which they can escalate their permissions levels. Detecting social engineering attacks requires human-centric vigilance, but available tools are designed specifically for detecting potential incidents involving escalated privileges.

Privilege escalation attacks can also be specific to operating systems, specifically Linux and Windows. Here are some of the most common examples of privilege escalation attacks based on each of these operating systems:

Linux Privilege Escalation

The open-source nature of Linux makes it susceptible to certain types of privilege escalation attacks, including:

• Kernel Exploitation: A common method in which attackers take advantage of vulnerabilities in the Linux kernel to gain root privileges. By exploiting these weaknesses, they can execute malicious payloads that enable them to perform malicious actions with escalated privileges.
• Enumeration: Threat actors gather information about the system, such as user accounts or network resources, that could be exploited for further attacks.
• SUDO Right Exploitation: Attackers often attempt privilege escalation by taking advantage of poorly configured sudo rights. If a privileged user has been careless with their sudo access permissions, an attacker may be able to leverage this oversight for their own ends.

Windows Privilege Escalation

Windows, another widely used operating system, faces its share of privilege escalation incidents primarily because many enterprises rely heavily on it for business operations. Here are some commonly used methods:

• Access Token Manipulation: This technique involves manipulating tokens associated with privileged accounts to trick the system into granting higher-level access than intended.
• Bypass User Account Control (UAC): An attacker might try bypassing UAC warnings designed to prevent unauthorized changes by using stealthy processes that don’t trigger these alerts.
• Sticky Keys: This attack replaces sethc(.exe) (the application responsible for Sticky Keys) with cmd(.exe) (Command Prompt), allowing anyone pressing SHIFT five times at the login screen to gain administrator privileges without needing credentials.

Detecting privilege escalation requires sophisticated security measures, given how subtly attackers operate when attempting these breaches. While the prevention and detection solutions above provide a suitable baseline, organizations often need additional support to keep their systems fully protected.

When mitigating the myriad of privilege escalation attacks, having a robust identity threat defense system is crucial. Proofpoint’s Identity Threat Detection and Response Solution offers an effective strategy to detect and respond to such threats.

Proofpoint’s comprehensive tool helps detect privilege escalation incidents by monitoring user accounts for suspicious activities or changes in behavior patterns. It employs advanced analytics to identify potential risks, including attempts to perform malicious actions or escalate privileges.

The platform is designed with sophisticated mechanisms that recognize vertical and horizontal privilege escalation techniques. Whether it’s an attacker trying to gain root privileges or a privileged user attempting unauthorized access to other users’ data, Proofpoint ensures immediate detection of these threats.

• Detecting Privilege Escalation: The tool effectively identifies any unusual activity like gaining access beyond one’s permission level, sudden changes in system administrator rights, sudo access misuse, etc., indicating possible privilege elevation attempts.
• Responding to Incidents: Upon detecting a potential incident where an attacker compromises security measures to take advantage of escalated privileges, Proofpoint immediately triggers alerts, enabling quick response from your IT team.
• Mitigating Risks: By applying the least-privilege principle rigorously across all systems (including Linux and Windows), it minimizes opportunities for attackers to attempt privilege escalation through credential theft or delivering malicious payload into your network infrastructure.

Besides this proactive approach to preventing attacks, Proofpoint helps organizations create secure environments by educating them about common examples of malicious actors exploiting system vulnerabilities to gain unauthorized access. This knowledge empowers businesses not just reactively but proactively to stay ahead of cybercriminals constantly evolving their tactics. Contact us today to find out more!