DETECTION OVERVIEW
Risk Factors
Microsoft released security bulletin MS14-025 to address a Group Policy Preferences (GPP) vulnerability that enabled attackers to decrypt passwords. However, unpatched systems and outdated group policy scripts might still rely on GPP. An attacker with SMB access to the SYSVOL share on a domain controller (DC) can leverage attack tools to easily enumerate encrypted passwords from GPP files and decrypt them. This type of credential access can help an attacker locate Windows devices to target.
The system might change the risk score for this detection.
Kill Chain
Risk Score
56
GPP is a collection of Group Policy extensions that enable Windows administrators to manage user and computer account passwords through group policies. GPP extensions are XML files that can store encrypted passwords and are referenced by group policy scripts. The GPP files are located in the SYSVOL share on a domain controller (DC). Any domain user can access the SYSVOL share and read GPP files to view cpassword values, which typically include encrypted passwords. Unfortunately, the private key needed to decrypt the passwords was unintentionally exposed to the public. Several attack tools, such as Metasploit, include modules that enumerate passwords from GPP files. For example, the attack tool sends an SMB READ request to access the XML with the cpassword attribute. The READ response sent to the attacker includes encrypted passwords, which are decrypted offline with the exposed private key.