What Is Privilege Escalation?

Privilege escalation is a step in the cyber attack chain. In this step, threat actors use their unauthorised access to an organisation’s systems and resources to give themselves deeper access by increasing their access higher privileges. With this access, they can carry out more significant attacks, like stealing confidential data or installing malware and ransomware.

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 themselves increased rights and admin capabilities, attackers can conduct malicious activities, potentially resulting in significant damages.

Systems have different levels of privileges, which range from basic users with limited permissions to administrators with complete control. A successful privilege escalation incident means that an attacker has managed to escalate their own privilege level, thereby gaining increased control.

Cyber attackers use privilege escalation to open up new attack vectors on a target system. This enables them to evolve attacks 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 unauthorised 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, when an attacker uses an employee's stolen credentials, this is horizontal privilege escalation. The goal here isn't necessarily to gain root privileges. Instead, the goal is to access sensitive information that belongs to other users within the same privilege level.

The key difference between these two types of attack lies in the kind of access the attacker seeks. With vertical escalation, an attacker takes advantage of vulnerabilities for elevated permissions. In contrast, with horizontal escalation the attacker exploits weak security practices among peers at similar permission levels.

Detecting both types of privilege escalation requires vigilance and robust cybersecurity measures. These measures include using security monitoring systems that detect unusual activity and implementing robust authentication methods. Organisations 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 often gain access to a system by finding weak points in an organisation's cybersecurity framework. Once the initial infiltration is successful, threat actors use specific vertical or horizontal privilege escalation strategies:

• Vertical. Attackers exploit vulnerabilities within the system or software applications to escalate their privileges from a basic user account up to privileged user levels, such as those held by system administrators. In these attacks, threat actors may also use social engineering techniques like phishing emails to trick users into granting access inadvertently or revealing sensitive information.
• Horizontal. In these attacks, threat actors focus on lateral movement across peer-level accounts. Oftentimes, they involve tactics like credential theft and session hijacking. Attackers 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 be carried out locally or remotely. Local privilege escalation attacks begin on-premises, typically by someone inside the organisation. 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. Organisations should ensure that their security measures are robust and regularly updated to prevent these types of cyberattacks.

Remember, no single method will catch every possible attack vector. Organisations need to have robust defences and proactive detection measures in place that use a combination of strategies.

Privilege escalation is a technique where a cyber attacker compromises a system to gain unauthorised access. This malicious activity can occur through various attack vectors, such as stolen credentials, 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 stealing credentials. Once they have credentials in hand, 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 principle of least privilege, 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. Detecting social engineering attacks requires human-centric vigilance. Luckily, tools are also available that can specifically detect incidents which may involve escalated privileges.

Privilege escalation attacks can also be specific to operating systems, specifically Linux and Windows.

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 escalate 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 take advantage of poorly configured sudo rights. If a privileged user has been careless with their sudo access permissions, an attacker may be able to use this oversight for their own ends.

Windows Privilege Escalation

Windows faces its share of privilege escalation incidents primarily because so many enterprises rely 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 unauthorised 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). This allows anyone pressing the “shift” key five times at the login screen to gain administrator privileges without needing credentials.

Detecting privilege escalation requires sophisticated security measures. While the prevention and detection solutions above provide a baseline, organisations often need additional support to keep their systems fully protected.

If you want to stop the myriad of privilege escalation attacks, you need a robust identity threat defence system. Proofpoint's Identity Threat Detection and Response solution helps you detect privilege escalation incidents by monitoring user accounts for suspicious activities or changes in behaviour. It uses advanced analytics to identify potential risks, including attempts to perform malicious actions or escalate privileges.

The platform is designed to recognise vertical and horizontal privilege escalation techniques. Whether it's an attacker trying to gain root privileges or a privileged user attempting unauthorised access to other users' data, Proofpoint can immediately detect these threats.

• Detect privilege escalation. Proofpoint identifies unusual activity like gaining access beyond a user’s permission level, sudden changes in system administrator rights, sudo access misuse and other actions that indicate attackers are trying to escalate privileges.
• Respond to incidents. When it detects a potential incident, Proofpoint immediately triggers alerts. This enables your IT team to respond quickly.
• Mitigate risks. By applying the principle of least privilege rigorously across all systems (including Linux and Windows), it minimises opportunities for attackers to attempt privilege escalation.

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