Authenticated spoofing via unsanitized URL input
Published Sep 15, 2021 · Updated Aug 10, 2026
Spoofing in Microsoft SharePoint Foundation 2013 and SharePoint Enterprise Server 2016 allows remote authenticated users to misdirect users via crafted web requests. SharePoint validates and sanitizes user-controlled URL input incorrectly, permitting a response or redirect that appears to originate from a trusted SharePoint site. Exploitation requires a victim to follow the crafted link, and the demonstrated consequence is user deception and possible disclosure of information to an attacker-controlled destination.
Summary
What happened
Spoofing in Microsoft SharePoint Foundation 2013 and SharePoint Enterprise Server 2016 allows remote authenticated users to misdirect users via crafted web requests. SharePoint validates and sanitizes user-controlled URL input incorrectly, permitting a response or redirect that appears to originate from a trusted SharePoint site. Exploitation requires a victim to follow the crafted link, and the demonstrated consequence is user deception and possible disclosure of information to an attacker-controlled destination.
The record
- CVE
- CVE-2021-38652
- Published
- Sep 15, 2021
- Updated
- Aug 10, 2026
- Vendor
- Microsoft
- Product
- Microsoft SharePoint Foundation 2013
- Classifications
- T1036
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 15, 2021CVE publishedPublication date reported by the CVE source.
- Aug 10, 2026Record 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=15.0.0 <5381.1000
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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