CVE-2025-29810 is a newly discovered security vulnerability affecting Microsoft’s Active Directory Domain Services (AD DS). This flaw allows an attacker—who already has some access (like a regular user)—to improperly gain higher privileges over a network, potentially taking full control over Windows domains.

This post breaks down how CVE-2025-29810 works, why it’s so severe, and how attackers might exploit it, with simple explanations and exclusive code snippets for demonstration.

The Heart of the Problem: Improper Access Control

Active Directory controls user and computer authentication inside most company networks. When there’s a weakness in how AD checks who can do what (called “access control”), a skilled attacker might trick it into letting them perform actions as an administrator.

In CVE-2025-29810, a flaw in the way object permissions and delegation are handled allows an attacker with basic network access (domain user) to gain elevated rights (like Domain Admin).

Who’s at risk: Any organization using unpatched Active Directory

The vulnerability involves improper enforcement of permissions. This means the system does not properly check whether a user really has permission to perform certain sensitive actions. Attackers exploit this with specific tools or code, escalating their privileges step by step.

Step 1: Attacker Gains a Footing

The attacker starts as an ordinary domain user. Maybe through phishing or another vulnerability, they have a valid username and password.

Step 2: Abusing Access Controls

The attacker uses tools (like PowerView or ADExplorer) to find AD objects where permissions are too loose. For CVE-2025-29810, they might look for cases where the “WriteDACL” or “GenericAll” permissions are set too broadly on sensitive objects (like user or group accounts).

Example PowerShell Snippet

# Show users/groups where current user has dangerous permissions (requires PowerView)
Import-Module .\PowerView.ps1
Get-DomainObjectAcl -Identity "Domain Admins" -ResolveGUIDs | ?{
    $_.ActiveDirectoryRights -match "GenericAll|WriteDacl"
}

Step 3: Triggering Privilege Escalation

Upon finding a vulnerable ACL, the attacker modifies the permissions to give themselves full control—or, in some variations, to reset the password of a domain admin account.

Example: Resetting an Admin Password

Set-ADAccountPassword -Identity "Administrator" -NewPassword (ConvertTo-SecureString "NewP@sswrd!" -AsPlainText -Force)

Upon success, the attacker logs in as Administrator. Now they own the domain.

Silent escalation: The attacker uses legit network features, so AV and EDR tools might miss it.

- Full control: Within minutes, attackers can take over servers, eject other admins, or deploy ransomware company-wide.
- Hard to detect: AD logs often don’t log detailed ACL changes or privilege escalations unless you have advanced auditing.

How To Fix CVE-2025-29810

Microsoft has released patches and security guidance for affected systems. IT admins should:

References and Further Reading

- Microsoft CVE-2025-29810 Security Advisory
- NIST National Vulnerability Database - CVE-2025-29810
- BloodHound Tool - AD Permission Analysis
- AD ACL Attacks & Defenses (SpecterOps)

Conclusion

CVE-2025-29810 is a major reminder that Active Directory security is only as strong as its weakest permission. Just one misconfigured ACL can let attackers climb to the very top of your network.

Patch now, audit your domain, and remember: the danger is not just hackers, but any over-permissioned user already inside your walls.

Timeline

Published on: 04/08/2025 18:16:06 UTC
Last modified on: 04/29/2025 22:55:49 UTC