Scanning the network for vulnerabilities to keep assets secure and intruders out is common practice. Organizations conduct periodic external scans to detect vulnerabilities, open ports and protocols. Internal scans are commonly used to identify at risk assets and provide insight into the patch management process. Microsoft Active Directory servers - a key component of many networks - contain information regarding all the objects within the domain, such as users, computers, applications, shared resources, and more. Many would not hesitate to protect the physical key for the front door, or lockbox, yet overlook an in-depth security analysis of a server in the data center.
Historically, when large data breaches are reported in the media, they are carried out by outside attackers. The reality is that insider attacks continue to make up a significant portion of data theft, and these attacks are the hardest to prevent. The increasing complexity of organizational networks and the growing interconnection of many IT dimensions, including OT, cloud, and web apps, has opened new opportunities for adversaries. To achieve lateral movement across their victims' many infrastructures, attackers now target the one system that connects everything together: Active Directory. AD is a favored target for attackers to elevate privileges and facilitate lateral movement through a network. If an external attack is successful in providing access to the inside protected network, poorly configured AD servers can provide additional privileges to a malicious actor.
Organizations also face additional challenges inside the network managing employees, contractors, consultants, guests, and other authorized users, all with varying levels of access. Insiders have advanced knowledge of organizational security practices, and know where data is stored. AD Vulnerabilities can potentially allow local attackers to escalate permissions and gain access to assets that would otherwise be restricted.
To respond to this growing threat, this report utilizes plugin output derived from a set of plugins that are part of the Tenable Active Directory Starter Scan Template. Active Directory attacks typically fall under 2 categories for 2 different motivations:
- Passwords and credentials protection.
- Privilege escalation & lateral movement prevention.
The Active Directory Starter Scan Template contains 10 hygiene checks that were chosen for their criticality, being often exploited by attackers seeking to navigate their targets' Active Directory. These plugins focus on the two most common attack paths and take aim at preventing attackers from guessing or cracking accounts’ secrets, impersonate other users, and limit the ability for attackers to obtain more rights and to move across domains.
Specifically, these components assist organizations in the identification of potentially hard to spot attacks such as Golden Ticket attacks. Outside of legacy protocols, weak passwords, and accounts with elevated privileges, Golden Ticket Attacks are the most common attack against AD servers. Golden Ticket attacks center around Kerberos and KRBTGT (Kerberous Ticket Granting Ticket) - such as Kerberoasting - which are typically trivial to successfully launch from the inside of the network. Kerberoasting is an attack which enables privilege exploitation, furthering the ability of an attacker to move laterally in the network.
These attacks are dangerous as the attacker does not require administrative rights. An attacker can merely request a service ticket from the Domain Controller and then use password cracking tools offline to retrieve plaintext credentials from vulnerable hashes. Additionally, AD vulnerabilities that can be a benefit to attackers in this process are also identified, such as Null Sessions, Primary Group ID, Weak Encryption, and Dangerous Trust Relationships.
Tenable.io unifies security data from across the organization, providing a comprehensive view and understanding of the organization's overall security posture. Using a diverse deployment of Nessus scanners, administrators have complete visibility into network connected assets with comprehensive vulnerability assessment coverage. When Active Directory concerns are identified, Tenable.io quickly provides alerts via workflows and notifications, which speed up incident response and vulnerability remediation. Additionally, Tenable.ad provides a comprehensive cyber exposure determination of Active Directory hosts.
List of Widgets
- Active Directory Account Related Findings: This widget displays Active Directory account related findings with account totals that contain Active Directory configuration improvement recommendations related to kerberoasting, primary group identity, non-expiring passwords, blank passwords, weak encryption, kerberos pre-auth, and unconstrained delegations. The plugins used in the widgets are part of the Active Directory Starter Scan Template and are meant to be used for preliminary analysis of AD hosts.
- Active Directory Vulnerabilities (Kerberos, Trusts Relationships, Null Sessions): This widget displays multiple Active Directory findings with relevant configuration improvement recommendations. Many of these configuration changes reduce an organization’s risk of exploitation. This widget uses plugins 150488,150484,150486 to list a total count of findings for assets that were identified with the associated vulnerabilities. These vulnerabilities represent misconfigurations that could lead to exploitation.
- Microsoft Active Directory Findings: This widget displays a vulnerability summary for assets that contain any vulnerabilities related to Active Directory. This widget uses the application CPE filter to cross reference all tenable plugins that contain active_directory. In addition to vulnerabilities gathered from the AD Starter Scan template, this widget will also display AD vulnerabilities from all relevant scans.
- Windows Account Information: This widget displays counts related to Microsoft Windows SMB plugins that focus on user account information. Plugins focus on vulnerabilities such as SMB blank administrator passwords, SMB password policies, guest accounts, cached passwords, and more. The widget provides detailed information and details of Windows SMB account concerns, to assist in determining if user accounts have any concerns that should be investigate further.
- Windows Group Memberships: This widget displays information for Windows default groups such as the administrators, server operators, account operators, backup operators, print operators, and replicator groups. The widget provides detailed information to assists in tracking group memberships and determining if elevated groups have unnecessary privileges.
- Windows User Account Information: This widget displays counts related to user accounts and security identifiers (SID). Plugins report on potential user account vulnerabilities such as disabled accounts, accounts that have never logged in, accounts with passwords that have never changed, and more. The widgets provides detailed information to assists in tracking user accounts and SIDs concerns, to assist in determining if user accounts have any concerns that should be investigate further.