Domain privilege escalation via RC4-MD4 downgrade
Published Apr 11, 2023 · Updated Jan 23, 2025
Weak cryptography in Windows Kerberos on affected Windows Server releases allows man-in-the-middle attackers to gain domain privileges. The KDC accepts an RC4-MD4-encrypted preauthentication timestamp and reuses its weak keystream, creating an oracle that exposes the TGT session key. A network-path attacker must intercept a client's AS-REQ and await authentication traffic; success grants the targeted account's privileges.
Summary
What happened
Weak cryptography in Windows Kerberos on affected Windows Server releases allows man-in-the-middle attackers to gain domain privileges. The KDC accepts an RC4-MD4-encrypted preauthentication timestamp and reuses its weak keystream, creating an oracle that exposes the TGT session key. A network-path attacker must intercept a client's AS-REQ and await authentication traffic; success grants the targeted account's privileges.
The record
- CVE
- CVE-2023-28244
- Published
- Apr 11, 2023
- Updated
- Jan 23, 2025
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-327, T1557
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 11, 2023CVE publishedPublication date reported by the CVE source.
- Jan 23, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.17763.0 <10.0.17763.4252
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- sk3w CVE-2023-28244 proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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