CVE-2023-24869
📋 TL;DR
CVE-2023-24869 is a Remote Procedure Call Runtime Remote Code Execution Vulnerability that allows an attacker to execute arbitrary code on affected systems by sending specially crafted RPC requests. This affects Windows systems with the RPC runtime component. The vulnerability can be exploited remotely without authentication.
💻 Affected Systems
- Microsoft Windows
📦 What is this software?
Windows 10 1507 by Microsoft
Windows 10 1607 by Microsoft
Windows 10 1809 by Microsoft
Windows 10 20h2 by Microsoft
Windows 10 21h2 by Microsoft
Windows 10 22h2 by Microsoft
Windows 11 21h2 by Microsoft
Windows 11 22h2 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with administrative privileges, enabling data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Remote code execution leading to malware installation, lateral movement within networks, and credential harvesting.
If Mitigated
Limited impact with proper network segmentation, RPC filtering, and endpoint protection blocking exploitation attempts.
🎯 Exploit Status
Microsoft rates this as 'Exploitation More Likely' in their advisory. The vulnerability requires no authentication and has low attack complexity.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: March 2023 security updates (KB5023696, KB5023697, etc.)
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-24869
Restart Required: Yes
Instructions:
1. Apply March 2023 Windows security updates via Windows Update. 2. For enterprise environments, deploy updates through WSUS or SCCM. 3. Restart systems after patch installation.
🔧 Temporary Workarounds
Block RPC Ports
windowsBlock inbound RPC traffic at network perimeter and between segments
netsh advfirewall firewall add rule name="Block RPC" dir=in action=block protocol=TCP localport=135,445,593
netsh advfirewall firewall add rule name="Block RPC UDP" dir=in action=block protocol=UDP localport=135,445
Disable RPC Endpoint Mapper
windowsDisable RPC endpoint mapper service to reduce attack surface
sc config RpcEptMapper start= disabled
sc stop RpcEptMapper
🧯 If You Can't Patch
- Implement strict network segmentation to isolate systems with RPC services
- Deploy endpoint detection and response (EDR) solutions with behavior-based blocking for RPC exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check Windows version and patch level: systeminfo | findstr /B /C:"OS Name" /C:"OS Version" /C:"Hotfix(s)"Check Version:
winverVerify Fix Applied:
Verify March 2023 security updates are installed: wmic qfe list | findstr "5023696 5023697"📡 Detection & Monitoring
Log Indicators:
- Windows Security Event ID 4688 (process creation) from RPC runtime
- Unexpected RPC service crashes in System logs
- Suspicious network connections to RPC ports
Network Indicators:
- Unusual RPC traffic patterns
- Multiple failed RPC authentication attempts followed by successful connections
- RPC requests with malformed packets
SIEM Query:
source="windows" (event_id=4688 OR event_id=4625) AND process_name="rpc*" AND (command_line CONTAINS "powershell" OR command_line CONTAINS "cmd")