Domain privilege escalation via weak RC4-HMAC negotiation
Published Nov 9, 2022 · Updated Aug 10, 2026
Kerberos authentication in Microsoft Windows Server allows remote attackers to gain domain privileges through weak RC4-HMAC negotiation. When account encryption types are unset, a domain controller falls back to RC4-HMAC session keys; MD5 collision substitution can alter signed, unencrypted traffic without the key. Exploitation requires an active network position, known plaintext, a colliding replacement, and a signed but unencrypted Kerberos-protected connection.
Summary
What happened
Kerberos authentication in Microsoft Windows Server allows remote attackers to gain domain privileges through weak RC4-HMAC negotiation. When account encryption types are unset, a domain controller falls back to RC4-HMAC session keys; MD5 collision substitution can alter signed, unencrypted traffic without the key. Exploitation requires an active network position, known plaintext, a colliding replacement, and a signed but unencrypted Kerberos-protected connection.
The record
- CVE
- CVE-2022-37966
- Published
- Nov 9, 2022
- Updated
- Aug 10, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- T1068
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 9, 2022CVE publishedPublication date reported by the CVE source.
- Aug 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
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Attacks
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Technologies
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