Group membership drift is a type of configuration drift in which users retain outdated permissions after switching roles, quitting a project, or obtaining unauthorized access. These permissions accumulate over time and lead to a “drift” away from any least privilege position, which can lead to security breaches.
Group membership drift grants users excessive privileges long-term, aiding attackers by providing them with more highly privileged accounts for lateral movement. This violates least privilege, elevates breach risk, and complicates compliance audits.
Common causes of Group Membership drift
- Temporary or emergency access that has been given and still active even when the situation has been resolved.
- People changing their roles or departments without removing their previous accesses, thus former employees or those who have been moved could still have unnecessary permissions.
- Manual group changes that are not approved or documented, thus ignoring the governance procedures.
- Nested groups that result in indirect and concealed access, when changes in subgroups are propagated unexpectedly.
Why Group Membership drift is dangerous
Group membership drift becomes an issue when privilege accumulation is left unchecked, and its effects cascade to the overall security posture.
- Insider Threats: Group membership drift increases the risk of insider threats by creating a larger total attack surface. Attackers make use of these types of accounts that may have lower levels of security monitoring to achieve privilege escalation while remaining undetected.
- Compliance Issues: Privilege creep causes audit failures and compliance violations, as outdated memberships contravene standards which require regular and prompt access reviews. Non compliance can lead to fines and increased regulatory scrutiny.
How to detect Group Membership drift
Detecting group membership drift starts with understanding who has access and who should have access as per their roles.
- Role-Based Reviews: Compare group membership at present with the role expectations defined earlier like job descriptions or HR policies. Mark as anomalies instances where users have been granted permissions that do not correspond with their current duties.
- Baseline Comparisons: Assess group members in relation to a baseline or approved list such as a configuration snapshot from the last audit. Focus on the differences in a group memberships that highlight the ones that have been added, removed, or changed since the baseline.
- Access Validation: Detects the users that should not have access anymore by checking group membership lists against employee status, department changes, or termination of employment records. Prioritize stale accounts based on your organization’s specific policies such as those that haven’t been used for more than 90 days or other predetermined boundaries.
- Manual Limitations: Manual detection becomes a very long and tedious job, it can take a weeks of work in a large environment. As it is reactive, finding the problems only during the rare audits, it also has a hard time to scale a thousands of groups.
Through continuous observation of group changes and warning of unauthorized or high risk additions, automated detection excels in doing what manual detection fails. Besides, it is better at figuring out nested and inherited memberships, something manual ways can’t achieve.
How to fix Group Membership drift
Fixing group membership drift needs fast, firm action to bring access back in line with actual requirements and reduce the attack surface.
- Remove Unauthorized Access: Make sure to remove unauthorized or old group memberships right away by shutting down lingering permissions of former employees, reassigned employees, or temporary roles. Concentrate on high-risk groups at first example those granting admin rights or access to sensitive data.
- Verify with Stakeholders: Verify the sufficiency of the access remaining by meeting with line managers or data owners to make sure it is justified with the present roles. Obtain the signature of the responsible party as evidence of the commitment to keep the membership covered.
- Clean Nested Groups: Remove the unused or dangerous nested groups by breaking down the complexity of the hierarchies wherever it is possible and getting rid of the unnecessary subgroups. Check the indirect routes of access to make sure there are no secret privileges and then deny them.
- Well-Documented Changes: Make sure all the changes to groups are well recorded or documented in a change log with the date and time, approvers, and the purpose. Use approval processes strictly for any future changes to avoid relapse.
How to prevent Group Membership drift
To prevent group membership drift, stop using reactive fixes and instead focus on proactive governance, which ensures that access is constantly aligned with roles. Here are a few strategies to prevent drift in group membership:
- Periodic Reviews: Conduct regular group membership checks and access audits, such as quarterly reviews that coincide with HR upgrades. To identify drift at its early stage, confirm group memberships with employee roles.
- Role-Based Access Control Alignment: Try to apply role-based access control (RBAC) that links permissions with job functions dynamically so that the system can automatically modify groups whenever roles are changed. This is one of the ways of ensuring that the members of the groups are those with the corresponding responsibilities and thus no need for manual intervention.
- Alerts to Sensitive Groups: Configure alerts for any changes made to highly sensitive or privileged groups, so that the admins get instant notifications of the additions, removals, or deletions. This method allows for quick reaction and thus unauthorized drift shall be prevented from the source.
- Minimizing Manual Group Management: Cut down on manual group changes by using automated provisioning extensively instead of making ad hoc edits. To reduce human errors in group changes, standardize the processes.
- Lease Privilege Enforcement: The users start with the bare minimum access needed. In order to incorporate least privilege and zero trust from the beginning, additional privileges are only briefly granted when necessary. Periodically review and certify permissions to eliminate anything unnecessary.
Conclusion
Maintaining strict access control to secure resources requires continuous monitoring of group membership changes instead of simply implementing one off fixes. Combining strong detection with prevention measures will allow the permission and role alignments to be continuously maintained.
Due to the inevitable changes in the personnel and their roles, group membership drift has become a constant challenge in environments that are always changing, not a simple task that can be taken off the list after doing it once.
Detection is the best tool for revealing the dangers that have been concealed, whereas prevention is the most effective way of stopping the problem from happening again. The two approaches together can be considered a single entity that keeps reducing the attack options available to criminals as time goes by.
If an organization wants to radically reduce its security vulnerabilities and compliance risks, it cannot afford to let these issues develop into serious problems before it reacts. The only way to do so is by having regular visibility of group changes and memberships.
How Lepide helps detect and prevent Group Membership drift
Lepide identifies group membership drift by using AI-driven real-time monitoring of Active Directory changes, detecting anomalies in user behavior at the data-level, and giving reports on direct/indirect memberships, effective permissions, and access paths of nested groups.
It assists in resolving drift by pointing out users with excessive privileges, keeping a record of permission changes historically, and facilitating automated remediation through custom policies that automatically revoke unnecessarily excessive access while at the same time ensuring least privilege and zero trust.
To learn how to identify and correct group membership drift in your Active Directory, schedule a personalized demo right now.
