Source: Dark Reading Author: Roy Akerman URL: https://www.darkreading.com/endpoint-security/how-to-protect-your-environment-from-the-ntlm-vulnerability

ONE SENTENCE SUMMARY:

A zero-day NTLM vulnerability allows attackers to steal credentials via viewing malicious files, posing significant security risks for enterprises.

MAIN POINTS:

1. Researchers discovered a zero-day vulnerability in NTLM affecting all Windows versions since 7 and Server 2008 R2.
2. Attackers can exploit this flaw by having users simply view a malicious file in Windows Explorer.
3. 64% of Active Directory accounts still authenticate using NTLM despite its deprecation and known weaknesses.
4. NTLM transmits password hashes, making them vulnerable to interception and relay attacks.
5. The vulnerability affects even those using NTLM v2, posing a risk for enterprises unprepared to move to Kerberos.
6. Microsoft advises adopting Extended Protection for Authentication and hardening LDAP configurations to mitigate risks.
7. Organizations should monitor SMB traffic and enable signing and encryption to protect against unauthorized access.
8. Legacy systems may still depend on NTLM, necessitating additional authentication layers like Dynamic Risk Based Policies.
9. Use Group Policy to audit and restrict NTLM traffic, identifying unnecessary dependencies on outdated protocols.
10. Transitioning to Kerberos and implementing Multi-Factor Authentication (MFA) are essential for improving security posture.

TAKEAWAYS:

1. NTLM vulnerabilities can allow widespread credential theft and unauthorized system access.
2. Proactive measures and configuration changes are critical for mitigating security risks linked to NTLM.
3. Organizations need to audit and update legacy systems relying on NTLM to prevent exploitation.
4. Monitoring and logging NTLM traffic can provide insights into potential attacks and remediation needs.
5. Shifting to modern authentication protocols like Kerberos, along with MFA, significantly enhances security resilience.