CVE-2014-1812

Microsoft Group Policy Preferences Password Leak in SYSVOL (CVE-2014-1812)

AI-generated analysis based on the vulnerability data on this page.

Summary

CVE-2014-1812 is a credential disclosure vulnerability in Microsoft Windows Group Policy Preferences. When administrators use Group Policy Preferences to set local account passwords, the credentials are stored in XML files within the domain's SYSVOL share. These passwords are encrypted with a hardcoded AES key that was published by Microsoft, making decryption trivial for any domain user with read access to SYSVOL.

Background

Group Policy Preferences (GPP) was introduced in Windows Server 2008 as a way to configure and deploy settings across Active Directory domains, including the creation of local user accounts and password changes. These preference files are stored in the SYSVOL share, which is replicated to all domain controllers and readable by all authenticated domain users. In May 2014, it was discovered that passwords configured through GPP were protected by reversible AES encryption using a publicly documented key.

Root Cause

This vulnerability stems from CWE-255: Credentials Management Issues. The implementation relied on a static, hardcoded AES encryption key to protect passwords stored in XML files on a share accessible to all authenticated users. Because the key was published in Microsoft documentation, the encryption provided no meaningful security boundary. Any authenticated domain user could read the XML files from SYSVOL and decrypt the embedded passwords, effectively bypassing the intended access control.

Impact

With a CVSS v2 score of 9.0 and a CVSS v3.1 score of 8.8, this vulnerability is rated as high severity. The metrics reflect that successful exploitation requires only low privileges (authenticated domain user) and low attack complexity, with network as the attack vector. The impact is complete across confidentiality, integrity, and availability: an attacker who obtains decrypted credentials can compromise local administrator accounts, move laterally across systems, and potentially gain domain-level privileges.

Exploitation Walkthrough

Note: This section is provided for defensive awareness only. The exploitation of this vulnerability against systems without authorization is illegal and unethical.

Attackers typically follow this pattern:

1. Enumerate the SYSVOL share on a domain controller for GPP XML files (commonly found in \\<domain>\SYSVOL\<domain>\Policies\).
2. Identify XML files containing the cpassword attribute, such as Groups.xml, ScheduledTasks.xml, Services.xml, or DataSources.xml.
3. Extract the cpassword value, which is the AES-encrypted password string.
4. Decrypt the cpassword using the publicly known AES key. This yields the plaintext password.
5. Use the recovered credentials to authenticate to affected systems, typically as a local administrator, enabling lateral movement and privilege escalation.

Affected and Patched Versions

This vulnerability affects:

• Windows Vista SP2
• Windows Server 2008 SP2 and R2 SP1
• Windows 7 SP1
• Windows 8
• Windows 8.1
• Windows Server 2012 Gold and R2

Microsoft addressed this in MS14-025, released on May 13, 2014. The update removed the ability to set passwords via Group Policy Preferences. For environments where patching is not possible, the recommended approach is to remove all GPP password entries and rotate any credentials that were previously deployed through this mechanism.

Remediation

1. Apply MS14-025: Install the security update from Microsoft that removes password configuration options from Group Policy Preferences.
2. Remove existing GPP passwords: Delete any cpassword entries from GPP XML files in SYSVOL and replace them with alternative credential management approaches.
3. Rotate compromised credentials: Any password ever deployed through GPP should be considered compromised and changed immediately.
4. Adopt Local Administrator Password Solution (LAPS): Use Microsoft LAPS to manage unique local administrator passwords across domain-joined machines, rather than deploying shared passwords via Group Policy.
5. Compensating controls: Restrict SYSVOL access to the minimum necessary, implement Group Policy filtering, and monitor for unauthorized access to the SYSVOL share.

Detection

• File analysis: Scan GPP XML files in SYSVOL for the presence of cpassword attributes. A non-empty cpassword indicates a stored encrypted password.
• Event logging: Monitor Windows Event Logs for suspicious authentication attempts using recovered local administrator credentials.
• Network monitoring: Alert on lateral movement patterns, such as pass-the-hash or remote service creation events, following authentication with known local admin accounts.
• SIEM queries: Create rules to detect access to SYSVOL shares from non-administrative workstations or at unusual times.

Assessment

CVE-2014-1812 remains a highly relevant vulnerability over a decade after disclosure. With an EPSS score of 0.65117 and a percentile of 0.99157, it sits in the top tier of exploited vulnerabilities and is included in the CISA Known Exploited Vulnerabilities (KEV) catalog since November 3, 2021. It has also been observed in ransomware operations. The key lesson is that reversible encryption of credentials—especially when the key is public—must never be treated as a security control. Organizations should treat any password ever deployed through GPP as potentially compromised, regardless of when the vulnerability was patched.

References

• Microsoft SRD Blog on MS14-025
• Microsoft Security Bulletin MS14-025
• CISA Known Exploited Vulnerabilities Catalog