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Last updated date : 01 Jun 2023

Linux environments are known for being a notorious management hazard. This is due to the criticality of their contents, such as credentials, SSH keys, service accounts, digital signatures, file systems, and so on, that form a crucial part of such environments. While most PAM vendors offer seamless privileged access management for Windows-based environments, they are not versatile enough to extend the same capabilities and functions for Linux, Unix, and *nix environments.

In this article, we will delve into the essentials of Linux privileged access management. Before getting into the know-hows, let us first identify and understand the most sensitive and integral cog of Linux environments—the root privilege.

What are root privileges in Linux?

In a Linux environment, a root user is the super account that performs administrative actions and is generally considered to hold the highest privileges. A user with root access has full-on administrative controls and has access to privileged files and system configurations.

Similar to sharing admin privileges to base users in a Windows environment, root privileges can also be shared to other users in a Linux environment. A user with root privileges in a Linux environment has all-out access to all servers and network corners, including critical database servers with limited command lines.

These corners of the network are normally not accessible for all users in a Linux environment, and are only shared to users on a case-by-case basis. With sharing of such crucial root privileges comes the security and operational hazard of gatekeeping shared access to limited and specific users, restricting shared access to limited command usage, and other necessary reduction of standing privileges.

Enforcing a privileged access management framework upon Linux environments can help admins automate the management of sensitive Linux resources and streamline the process of privilege sharing and access provisioning.

Sharing root privileges in Linux environments

Conventionally, su (switch user) and sudo (switch user and do) are Linux commands that allow users to perform actions with root privileges. The su command allows users to perform root commands if the user possesses the root credentials. However, the sudo command lets users run root commands without the use of root credentials. sudo offers a more tangible solution to root escalation by elevating the current user to that of a root user. Such Linux root access provisions can be regulated, customized, audited, and monitored when subject to a privileged access management protocol.

Why should organizations protect their Linux environments?

  • 01.

    Privilege escalation attacks

    Essentially, when a user account on a Linux system is used to perform root operations, it is known as root privilege escalation. In other words, a root account can be misused to gain unauthorized access to sensitive endpoints and resources that are home to multiple business-critical applications and processes. However, with appropriate access control policies and workflows in place, admins can grant and ensure secure access to such critical systems in a time-limited fashion.

  • 02.

    Rogue insider threats

    More often than not, privilege misuse attacks come in the disguise of a rogue insider. This is a rapidly growing trend that is visible in organizational hierarchy of all sizes. Standing privileges are often weaponized by rogue insiders in order to take control of entire IT ecosystems from within. To avoid such situations, it is important to define clear boundaries with respect to privileges that are shared across the Linux network. This will help in eradicating standing privileges and thus reducing potential rogue insider attacks.

  • 03.

    Third-party vendor privilege abuse

    It is common practice for enterprise IT teams to collaborate with third-party organizations for extended business solutions provided by auditors, consultants, partners, maintenance personnel, and even programmers. Provisioning additional unnecessary privileges to such third-party collaborators leads to standing privileges that are often forgotten about. This kind of access provisioning can result in privilege abuse attacks.

How can enterprises ensure privileged access security in their Linux and Unix environments?

Imposing a privileged access security routine with the use of PAM solutions will empower IT administrators to enforce granular governance over Linux privileged access management. Here's how Linux privileged access management can help streamline this routine for IT teams.

01. Secure account onboarding

Periodically discover and onboard Linux endpoints from across the enterprise network. These machines are stored and accessible centrally in a single platform that increases the visibility of endpoints in otherwise siloed Linux networks. These machines can then be grouped organizationally according to hierarchical demands.

02. Automated remote password reset

Once all the endpoints and the associated accounts are onboarded, password policies can be enforced. These policies can be designed using the PAM tool based on internal security requirements. These tools also come with native password generators that allow seamless and periodic rotation of passwords on both scheduled and on-demand bases. Further, PAM tools offer real-time audits on all password-related activities, such as password resets, sharing, and check-outs.

03. Seamless privilege escalation

  • a.

    Just-in-time (JIT) access

    With JIT capabilities that any Linux privileged access management framework brings to the table, admins can allow time-restricted sharing of privileged Linux accounts to users. Such users subject to JIT access will have access to shared passwords of privileged Linux accounts until the stipulated timeframe. Access to the endpoint is terminated and the passwords are reset instantly upon expiry of said time to prevent any unauthorized access attempts in the future.

  • b.

    Command control

    Through command control, IT admins can restrict users from executing certain privileged SSH commands, such as the rm command, which is used to delete files. Admins can specify a group of Linux commands that can be allow listed, after which users who are subject to such access restrictions are allowed to execute only those particular commands.

    Furthermore, using command control, a Linux user can be allowed, upon need, to execute such sensitive commands with elevated privileges if necessary. This allows a non-root user account to perform root actions without actually sharing the root credentials.

    To implement such Linux privileged access management controls enterprise-wide, organizations tend to lean toward pursuing a PAM solution.

Best practices associated with Linux privileged access management

  • Maintain a comprehensive record of all currently active privileged accounts within your Linux environment and ensure that the record is regularly updated as and when necessary.
  • Store your privileged Linux identities, such as passwords and SSH keys, in a secure vault that utilizes a standardized encryption algorithm.
  • Secure your Linux endpoints by implementing strict password policies, enforcing regular password resets, generating strong SSH key pairs, and automatically resetting such identities after a single use.
  • Share all endpoints, applications, and resources in your Linux environment with third-party collaborators securely by following the principle of least privilege, and ensure all standing privileges are revoked immediately.
  • Audit and record every action performed in your Linux environment, be it a user's SSH session, a password reset, or sharing of privileges. This will help admins with damage control and prevention, and enable them to execute immediate break-glass measures.

Linux privileged access management with PAM360

ManageEngine PAM360 is a one-stop enterprise PAM solution that offers a central console for effective Linux privileged access management. It helps IT teams automatically discover, store, manage, and audit access privileged accounts, SSH keys, and digital certificates. With PAM360, IT administrators can put the entire process of privileged access management for Linux and Unix environments on auto-pilot, and proactively combat insider threats and privilege abuse attacks.