Locked-session access via cached-credential RDP reconnection
Published Jan 15, 2020 · Updated Sep 17, 2024
Authentication bypass in Microsoft Windows Server 2019 and later allows local users to access a locked RDP session after reconnection. Automatic Reconnection reuses credentials cached by the RDP client and restores the remote session to an unlocked desktop without invoking the lock-screen credential prompt. Exploitation requires access to the RDP client and interruption of its network connection; Microsoft disputes that this behavior crosses a security boundary.
Summary
What happened
Authentication bypass in Microsoft Windows Server 2019 and later allows local users to access a locked RDP session after reconnection. Automatic Reconnection reuses credentials cached by the RDP client and restores the remote session to an unlocked desktop without invoking the lock-screen credential prompt. Exploitation requires access to the RDP client and interruption of its network connection; Microsoft disputes that this behavior crosses a security boundary.
The record
- CVE
- CVE-2019-9510
- Published
- Jan 15, 2020
- Updated
- Sep 17, 2024
- Vendor
- Microsoft
- Product
- Windows Server
- Classifications
- CWE-288, CWE-755, T1563.002
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 15, 2020CVE publishedPublication date reported by the CVE source.
- Sep 17, 2024Record 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=2019 <2019*
What conditions does exploitation require?
What is affected?
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
- CERT/CC locked-session reconnection procedureproof 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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