CVE-2022-29110
📋 TL;DR
This vulnerability allows remote code execution through specially crafted Excel files. Attackers can exploit this by tricking users into opening malicious documents, potentially taking full control of affected systems. All users running vulnerable versions of Microsoft Excel are affected.
💻 Affected Systems
- Microsoft Excel
📦 What is this software?
Excel by Microsoft
Excel by Microsoft
Excel by Microsoft
Excel by Microsoft
Excel by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining administrative privileges, data exfiltration, ransomware deployment, and persistent backdoor installation.
Likely Case
Local privilege escalation leading to data theft, credential harvesting, and lateral movement within the network.
If Mitigated
Limited impact with proper application whitelisting, macro restrictions, and user training preventing malicious file execution.
🎯 Exploit Status
Requires social engineering to deliver malicious Excel file. No public exploit code available as of last update.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: May 2022 security updates
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2022-29110
Restart Required: Yes
Instructions:
1. Open Microsoft Excel. 2. Go to File > Account > Update Options > Update Now. 3. Install available updates. 4. Restart computer if prompted.
🔧 Temporary Workarounds
Block Excel file types via Group Policy
windowsPrevent execution of Excel files from untrusted sources
gpedit.msc > Computer Configuration > Windows Settings > Security Settings > Software Restriction Policies
Disable macros in Excel
windowsPrevent macro execution which could be used in exploitation
File > Options > Trust Center > Trust Center Settings > Macro Settings > Disable all macros without notification
🧯 If You Can't Patch
- Implement application whitelisting to only allow trusted Excel executables
- Deploy email filtering to block suspicious Excel attachments and train users not to open unexpected files
🔍 How to Verify
Check if Vulnerable:
Check Excel version via File > Account > About Excel. If version is before May 2022 updates, system is vulnerable.Check Version:
powershell Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\*" | Where-Object {$_.DisplayName -like "*Excel*"} | Select-Object DisplayName, DisplayVersionVerify Fix Applied:
Verify Excel version shows May 2022 or later updates installed in File > Account > About Excel.📡 Detection & Monitoring
Log Indicators:
- Windows Event Logs showing Excel crashes, suspicious child processes spawned from Excel.exe
- Process creation events for unexpected executables from Excel
Network Indicators:
- Outbound connections from Excel process to unknown external IPs
- DNS queries for command and control domains from Excel
SIEM Query:
source="windows" process_name="excel.exe" AND (event_id=1 OR event_id=4688) AND parent_process_name NOT IN ("explorer.exe", "winword.exe")