CVE-2022-47508 in SolarWinds
Summary
by MITRE • 02/15/2023
Customers who had configured their polling to occur via Kerberos did not expect NTLM Traffic on their environment, but since we were querying for data via IP address this prevented us from utilizing Kerberos.
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Analysis
by VulDB Data Team • 02/15/2023
This vulnerability represents a critical authentication misconfiguration issue affecting systems that rely on Kerberos for secure authentication. The flaw occurs when customer environments are configured to use Kerberos authentication for polling operations but unexpectedly encounter NTLM traffic patterns. The root cause stems from the system's inability to properly handle authentication protocols when queries are directed through IP addresses rather than fully qualified domain names. This creates a scenario where the authentication mechanism fails to establish proper Kerberos sessions, forcing the system to fall back to less secure NTLM protocols. The vulnerability exposes systems to potential man-in-the-middle attacks and credential interception risks, as NTLM lacks the encryption and integrity protection mechanisms inherent in Kerberos authentication.
The technical implementation flaw manifests when the system attempts to resolve target endpoints through IP address lookups rather than DNS resolution. This approach bypasses the Kerberos pre-authentication mechanisms that typically occur during domain name resolution, forcing authentication to occur through the NTLM protocol stack. The vulnerability directly relates to CWE-287 which addresses improper authentication issues and aligns with ATT&CK technique T1550.001 for use of Kerberos authentication. When systems query targets via IP addresses, the authentication service cannot properly negotiate Kerberos tickets, resulting in protocol downgrade to NTLM which is more susceptible to credential theft and replay attacks. This misconfiguration creates a security boundary failure where the intended secure authentication mechanism is circumvented.
The operational impact of this vulnerability extends beyond simple authentication failures to encompass significant security risks for enterprise environments. Organizations may experience unauthorized access to sensitive data and systems when NTLM fallback occurs, as NTLM is vulnerable to various attack vectors including credential relay attacks and password spraying techniques. The vulnerability particularly affects environments where Kerberos is the primary authentication protocol but network configurations force IP-based communication. This creates a persistent security gap where legitimate users may be authenticated through NTLM instead of Kerberos, potentially allowing attackers to exploit the weaker authentication mechanism. The issue becomes more pronounced in environments with strict security policies that mandate Kerberos usage, as this vulnerability effectively bypasses those security controls.
Mitigation strategies should focus on implementing proper DNS resolution mechanisms and ensuring that all authentication queries utilize fully qualified domain names rather than IP addresses. Organizations should configure their systems to enforce Kerberos authentication and disable NTLM fallback mechanisms where possible. Network segmentation and firewall rules should be implemented to prevent IP-based communication patterns that trigger the vulnerability. The implementation of secure authentication policies and regular monitoring of authentication protocols can help detect when NTLM fallback occurs unexpectedly. Security teams should also consider implementing authentication auditing and alerting mechanisms that notify administrators when Kerberos authentication fails and NTLM is automatically used as a fallback. These measures align with security frameworks such as NIST SP 800-171 and ISO 27001 requirements for secure authentication management and protocol enforcement.