In the world of cybersecurity, gaining initial access is often just the beginning. Attackers rarely stop at entry points they aim to move deeper into systems, gain higher-level permissions, and ultimately take full control of the environment. This process, known as privilege escalation, is a critical phase in modern cyberattacks and often determines whether an incident remains contained or evolves into a full-scale breach.
Privilege escalation takes place when either a user or a process has acquired permissions that would otherwise be restricted. An example of privilege escalation is when an attacker moves up through the privileges of users from a standard user to an administrator or root level user (vertical escalation) or accesses data of someone else who has the same level of privilege (horizontal escalation). Although both can be harmful, vertical escalation will typically have a greater impact as it gives someone control over critical system operations.
Gaining access to a victim’s network is only half of the successful attack in modern cyber warfare. After gaining access to the network, attackers will continue to migrate through the target environment to gain additional access to levels of higher privilege. At this point (which cyber attackers refer to as “privilege escalation”), attackers will usually have complete control of the target network. The escalation phase of an attack will determine whether the cyber attack results in a contained incident or if a significant amount of data is breached.
When a user or process enters an area that has been reported as having specific user permissions, he/she has committed an act of privilege escalation.
Once the act of privilege escalation has been achieved, the attacker can:
The vast majority of investigations into cyber incidents have indicated that this phase of the incident typically represents the transition from being an uncontrolled incident to a total compromise of the organization's data.
There are many different methods of performing an act of privilege escalation. Attackers often use a combination of several types of privilege escalation techniques, based upon the target's network environment and any vulnerabilities that have been identified.
Improperly configured user rights in file systems, folders, and services can provide a privilege escalation opportunity for an attacker to carry out an attack. The attacker may use this vulnerability to create files, or to modify or delete files on the service or on the system with user privileges granted to them.
Any operating system that has not been patched contains vulnerabilities in the kernel that hackers can exploit to gain complete control over the system. This makes kernel exploits one of the most effective and dangerous means of escalating privileges.
There are many services running as high privilege accounts that can be targeted through misconfiguration. Typical vulnerabilities in service configurations that could be leveraged by an attacker would include unquoted paths, writable binaries and permissions being improperly set. All of these misconfigured services may be exploited by an attacker to execute malicious code.
Access Tokens are the mechanism by which Windows manages privileges. If an attacker can steal or impersonate a privileged process access token, they may be able to elevate their access without having to possess the directly associated credentials.
Automated tasks which run as elevated privileges may be leveraged by an attacker if the configuration file or script that corresponds to the task is writable. An attacker may modify the configuration file/script to execute their malicious code during execution of the scheduled task.
In the current state of cloud computing, there can exist a lack of appropriate controls that allow for effective separation between one or more containers within the same cloud. An intruder may take advantage of these weaknesses and escape from his/her container to gain access to the host, which can potentially lead to compromising all of the infrastructure.
To stop privilege escalation requires that the security policies you implement include both prevention and detection and be applied in a layered approach. Mainly, there are three significant steps to take in order to prevent the escalation of privileged user status:
Credentials must be protected with secured storage and multi-factor authentication. You should also continuously monitor your systems for abnormal privilege level changes or suspicious activity.
If you've put in place these preventive security measures, you should have confidence that even if someone is able to successfully compromise an account or system, an attacker would not have sufficient privileges to escalate their level of permission.
Privilege escalation plays a critical role in the attack lifecycle and provides an attacker with a means to extend their access and control of the network, bypass existing defenses, and ultimately accomplish their objectives. Nevertheless, organizations can implement the right security policies and maintain sufficient visibility into their environment to minimize the potential impact of an attack at this stage of the attack lifecycle through the implementation of the appropriate security policies and procedures.
Ancrew Global Services provides advanced cybersecurity services, including vulnerability assessments, penetration testing, and privilege escalation detection strategies to help organizations identify weaknesses and secure their environments against evolving threats.