SYSTEM privilege escalation via temporary-directory DLL hijacking
Published Jan 25, 2024 · Updated Jun 3, 2025
Local privilege escalation in Splashtop Software Updater 1.5.6.21 and earlier allows local users to execute code as SYSTEM. During uninstall, uninst.exe creates C:\Windows\Temp~nsu.tmp with inherited Temp permissions, copies itself there as Au_.exe, and loads a user-writable DLL when Au_.exe runs. A standard user can plant the DLL, then gain SYSTEM privileges after a reboot or an MSI repair of Splashtop Streamer launches Au_.exe.
Summary
What happened
Local privilege escalation in Splashtop Software Updater 1.5.6.21 and earlier allows local users to execute code as SYSTEM. During uninstall, uninst.exe creates C:\Windows\Temp~nsu.tmp with inherited Temp permissions, copies itself there as Au_.exe, and loads a user-writable DLL when Au_.exe runs. A standard user can plant the DLL, then gain SYSTEM privileges after a reboot or an MSI repair of Splashtop Streamer launches Au_.exe.
The record
- CVE
- CVE-2023-3181
- Published
- Jan 25, 2024
- Updated
- Jun 3, 2025
- Vendor
- Splashtop
- Product
- Splashtop Software Updater
- Classifications
- CWE-379, T1574.001
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 25, 2024CVE publishedPublication date reported by the CVE source.
- Jun 3, 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=0 <1.5.6.21
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
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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