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How the CVE Works
CVE-2025-53770 is a deserialization vulnerability in Microsoft SharePoint Server where untrusted data is improperly processed during serialization. An attacker can craft malicious payloads that, when deserialized by SharePoint, execute arbitrary code remotely. This occurs due to insufficient validation of user-supplied input during object reconstruction, allowing remote code execution (RCE) over the network. The exploit leverages .NET deserialization flaws, enabling attackers to bypass security mechanisms and gain SYSTEM-level privileges on affected servers.
DailyCVE Form
Platform: Microsoft SharePoint Server
Version: 2016, 2019, Subscription (<16.0.18526.20508)
Vulnerability: Deserialization RCE
Severity: Critical
Date: 2025-07-20
Prediction: Patch expected by 2025-07-28
What Undercode Say
Analytics:
Get-SPFarm | Select Servers
Get-SPServiceApplication | Where {$_.TypeName -like "Serialization"}
curl -X POST "http://<target>/_vti_bin/client.svc" -H "Content-Type: application/json" --data-binary @payload.bin
How Exploit
- Craft malicious serialized .NET payload.
- Send payload via SharePoint client.svc endpoint.
- Trigger deserialization for RCE.
Protection from this CVE
- Enable AMSI integration.
- Deploy Defender AV on SharePoint servers.
- Block public-facing SharePoint instances.
Impact
- Remote SYSTEM-level compromise.
- Unauthorized data access.
- Full server control.
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
