Authenticated code execution via unsafe TypeConverter deserialization
Published Apr 15, 2020 · Updated Aug 4, 2024
Deserialization in Microsoft SharePoint 2013 SP1, 2016, and 2019 allows remote authenticated users to execute code via WebPart XML. WebPartPages.asmx accepts attacker-chosen property type names and text, then ImportWebPartFile selects the named .NET TypeConverter and converts the text into an object that reaches BinaryFormatter deserialization. Exploitation requires Add or Customize Pages permission; default site creation grants an authenticated user that access, and code runs as the SharePoint web application service account.
Summary
What happened
Deserialization in Microsoft SharePoint 2013 SP1, 2016, and 2019 allows remote authenticated users to execute code via WebPart XML. WebPartPages.asmx accepts attacker-chosen property type names and text, then ImportWebPartFile selects the named .NET TypeConverter and converts the text into an object that reaches BinaryFormatter deserialization. Exploitation requires Add or Customize Pages permission; default site creation grants an authenticated user that access, and code runs as the SharePoint web application service account.
The record
- CVE
- CVE-2020-0932
- Published
- Apr 15, 2020
- Updated
- Aug 4, 2024
- Vendor
- Microsoft
- Product
- Microsoft SharePoint Server
- Classifications
- CWE-434, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 15, 2020CVE publishedPublication date reported by the CVE source.
- Aug 4, 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?
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- Affected versionversion=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
- ZDI SP_soap_RCE_PoCfunctional · demonstrated
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Technologies
Your stack
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Your stack
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