5 critical vulnerabilities and how real-time monitoring strengthens Active Directory security

Did you know that every day, there are 95 million attacks on Active Directory? As the backbone of enterprise identity and access management, AD is a prime target for threat actors seeking to gain privileged access and move laterally across networks.

This webpage explores the five most exploited AD vulnerabilities and how to detect, respond to, and harden your defenses using purpose-built security tools. Here are the various vulnerabilities:

1. Excessive privileges and over-provisioned accounts in AD

In many enterprise environments, users are granted more permissions than necessary for their job functions, often due to:

• Role changes without corresponding privilege revocation.
• Poorly managed group policies or nested group structures.
• Temporary elevation of privileges that are never rolled back.

These over-privileged accounts, especially when they have domain admin or elevated rights, are highly attractive to attackers because these often enable them to:

• Move laterally across systems.
• Execute malicious administrative tasks.
• Access sensitive data without being noticed.

Here is how the vulnerability occurs:

1. Initial user provisioning: Users are added to multiple groups to “make things easier,” often including ones with elevated access.
2. Role drift: As users change departments or roles, their previous privileges are not revoked.
3. Service account mismanagement: Service accounts are created with domain-level privileges and reused across systems.
4. Privilege inheritance: Through nested group memberships, users inherit admin rights indirectly.
5. Lack of visibility: IT admins lack visibility into who has what permissions, especially in large domains.

These attacks can be carried out with the vulnerability mentioned above:

• Privilege escalation: Attackers elevate rights using tools like net localgroup or PowerView.
• Kerberoasting: Over-privileged service accounts with weak passwords are exploited to extract hashes.
• Pass-the-hash and Pass-the-ticket: Harvested hashes or tickets from over-privileged sessions are reused.
• Lateral movement: Compromised users are exploited to access sensitive systems across the network.

Here are the ways that a SIEM solution helps prevent these attacks:

Here are the ways that an IAM solution helps prevent these attacks:

2. Unused, stale, orphaned AD accounts

In most organizations, as employees leave or shift roles, their AD user accounts might be:

• Unused: Created but never logged into.
• Stale: Not used for months or years.
• Orphaned: Still active even after employee offboarding due to HR-IT sync gaps or mismanaged life cycle policies.

These accounts often retain group memberships, access to systems, mailboxes, and VPN, effectively making them backdoors that attackers can exploit without triggering alerts tied to active users.

Here is how the vulnerability occurs:

1. Account creation: User accounts are created for employees, contractors, or service integrations.
2. Lack of usage monitoring: These accounts aren’t tracked for activity, especially if they’re temporary or unused.
3. Role or employment changes: Employees change roles, leave, or are terminated, but their accounts remain enabled.
4. Privilege retention: These accounts still belong to privileged groups (Domain admins, Remote desktop users, etc.).
5. Lack of cleanup policies: No automated or manual review process to flag or remove dormant accounts.

Here are attacks that can be carried out with the vulnerability mentioned above:

• Account hijacking: Attackers take control of a dormant but valid account to avoid detection.
• Credential stuffing: Using breached credentials to log into stale accounts that haven’t had passwords reset in years.
• Lateral movement: Using old accounts that retain admin access or permissions to pivot inside the network.
• Persistence establishment: The attacker creates a rogue account, disables it, and re-enables it later to maintain access.

Here are the ways that a SIEM solution helps prevent these attacks:

Here are the ways that am IAM solution helps prevent these attacks:

3. Misconfigured group policies and insecure defaults

GPOs in Active Directory control everything from password policies and RDP access to firewall settings and script execution. When these policies are misconfigured or left at insecure defaults (for example, unrestricted software installations), they create wide attack surfaces that can be silently abused.

Common insecure defaults or misconfigurations include:

• Overly permissive security settings (for example, No User Account Control (UAC), and Allow remote desktop)
• Scripts with admin privileges deployed via GPO
• GPOs linked to wrong OUs, affecting unintended user groups
• Lack of audit settings that could detect suspicious changes

Here is how the vulnerability occurs:

1. Initial setup: GPOs are configured once and often not revisited.
2. Delegation without review: Junior admins might be given GPO modification rights without tight controls.
3. Shadow GPOs: Attackers or rogue insiders might create GPOs with minimal settings that serve as a backdoor.
4. Privilege escalation via GPO: Malicious actors can link GPOs to inject startup scripts, deploy malware, or elevate local privileges.

Here are the attacks that can be carried out with the vulnerability mentioned above:

• GPO abuse for malware deployment: Attackers push malicious scripts or registry edits via GPO to multiple machines.
• Credential theft via script injection: Attackers inject scripts that capture credentials or set up keyloggers on login.
• Privilege escalation: Attackers modify GPOs to disable UAC, enable RDP, or grant local admin rights.
• Persistence mechanism: Attackers add tasks or services that run on startup via GPO, maintaining long-term access.
• GPO slide loading: Attackers create benign-looking GPOs linked to OUs with no logging and auditing enabled.

Here are the ways that a SIEM solution helps prevent these attacks:

Here are the ways that an IAM solution helps prevent these attacks:

4. Weak or exposed authentication mechanism

This vulnerability arises when organizations rely on outdated, misconfigured, or easily exploitable authentication methods. In AD environments, this typically includes:

• Use of NTLM instead of Kerberos
• Lack of MFA
• Password policies that allow weak or reused credentials
• Service accounts with hard-coded credentials
• Plaintext credentials in scripts or GPOs
• Legacy protocols like LDAP without TLS

Such weaknesses give bad actors opportunities to inflict brute-force attacks, replay or extract credentials, or move laterally using stolen tokens.

Here is how the vulnerability occurs:

1. Credential discovery: Attackers use techniques like Kerberoasting, LSASS memory dumps, or look for cleartext credentials in scripts, GPOs, or shares.
2. Brute-force and Spray attacks: Attackers automate login attempts using password dictionaries or previously breached credentials.
3. NTLM relay and Pass-the-hash: Exploiting legacy protocols, attackers relay credentials between systems or replay hashes to gain access.
4. Privilege escalation: Once authenticated, attackers move laterally or escalate privileges using compromised tokens.
5. Persistence setup: Adversaries might create new accounts, schedule tasks, or inject backdoors after gaining privileged access.

Here are the attacks that can be carried out with the vulnerability mentioned above:

• Kerberoasting: Extracting and cracking service account tickets to retrieve plaintext passwords.
• Brute-force and password spray: Guessing passwords against multiple users until one works.
• Pass-the-hash and NTLM relay: Reusing password hashes to authenticate without needing the actual password.
• Golden ticket attack: Forging Kerberos tickets to impersonate users, including domain admins.
• Credential dumping: Stealing stored credentials from memory using tools like Mimikatz.

Here are the ways that a SIEM solution helps prevent these attacks:

Here are the ways that an IAM solution helps prevent these attacks:

5. Insecure delegation and ACL misconfiguration

Delegation in AD allows a service or an account to act on behalf of a user, typically to access resources. There are three types of delegation:

• Unconstrained delegation: Full impersonation to any service on behalf of a user, which is very risky.
• Constrained delegation: Limited to specific services.
• Resource-based constrained delegation (RBCD): Delegation controlled by the resource, not the domain admin.

Access control list (ACL) misconfigurations occur when overly permissive permissions are applied to AD objects (users, groups, OUs), allowing unauthorized users to read/write sensitive attributes or escalate privileges.

Here is how the vulnerability occurs:

• Reconnaissance:
  • Attackers enumerate accounts with unconstrained delegation or custom ACL permissions.
  • Identify misconfigured GenericWrite, WriteDACL, or WriteOwner rights on high-value objects.
• Compromise and abuse:
  • Use tools like PowerView, BloodHound, or ADExplorer to map vulnerable paths.
  • Exploit ACLs to escalate privileges by modifying group membership, GPOs, or permissions.
• Persistence and lateral movement:
  • Abuse delegation or modified ACLs to impersonate privileged users.
  • Create backdoor accounts with inherited privileges or set malicious permissions.

The following are the attacks that can be carried out with the vulnerability mentioned above:

• Unconstrained delegation abuse: Attackers gain access to a system with unconstrained delegation and impersonate domain users.
• Resource-based constrained delegation abuse: Compromise a machine and manipulate RBCD to impersonate domain admins.
• DCSync attack via ACL abuse: Grant Replicating Directory Changes permission to an account to extract password hashes from the domain controller.
• Object takeover via GenericWrite: Modify attributes like member, logonScript, or msDS-AllowedToActOnBehalfOfOtherIdentity.

Here are the ways that a SIEM solution helps prevent these attacks:

Here are the ways that an IAM solution helps prevent these attacks:

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