CVE-2024-20728
📋 TL;DR
CVE-2024-20728 is an out-of-bounds write vulnerability in Adobe Acrobat Reader that could allow arbitrary code execution when a user opens a malicious PDF file. This affects users of Adobe Acrobat Reader versions 20.005.30539, 23.008.20470 and earlier. Successful exploitation requires user interaction through opening a malicious document.
💻 Affected Systems
- Adobe Acrobat Reader DC
- Adobe Acrobat Reader
📦 What is this software?
Acrobat by Adobe
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control of the victim's computer in the context of the current user, potentially leading to data theft, ransomware deployment, or lateral movement within a network.
Likely Case
Malicious actor gains code execution on individual workstations, enabling credential theft, data exfiltration, or installation of persistent malware.
If Mitigated
Limited impact with proper application sandboxing, least privilege user accounts, and network segmentation preventing lateral movement.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file). No public exploit code available at time of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 20.005.30554, 23.008.20476 and later
Vendor Advisory: https://helpx.adobe.com/security/products/acrobat/apsb24-07.html
Restart Required: Yes
Instructions:
1. Open Adobe Acrobat Reader. 2. Go to Help > Check for Updates. 3. Follow prompts to install available updates. 4. Restart the application when prompted.
🔧 Temporary Workarounds
Disable JavaScript in Adobe Reader
allPrevents JavaScript-based exploitation vectors that might be used in conjunction with this vulnerability
Edit > Preferences > JavaScript > Uncheck 'Enable Acrobat JavaScript'
Use Protected View
allOpen PDFs in Protected View mode to limit potential damage
File > Open > Select 'Protected View' option when opening files from untrusted sources
🧯 If You Can't Patch
- Implement application whitelisting to block unauthorized PDF readers
- Use network segmentation to isolate PDF processing workstations
🔍 How to Verify
Check if Vulnerable:
Check Adobe Acrobat Reader version via Help > About Adobe Acrobat Reader DCCheck Version:
On Windows: Get-ItemProperty 'HKLM:\SOFTWARE\Adobe\Acrobat Reader\DC\Installer' | Select-Object -ExpandProperty VersionVerify Fix Applied:
Verify version is 20.005.30554 or later for Continuous track, or 23.008.20476 or later for Classic track📡 Detection & Monitoring
Log Indicators:
- Unusual process creation from AcroRd32.exe or Acrobat.exe
- Multiple failed PDF parsing attempts
- Unexpected network connections from PDF reader process
Network Indicators:
- Outbound connections from PDF reader to suspicious domains
- Unusual DNS queries for PDF-related resources
SIEM Query:
process_name:('AcroRd32.exe' OR 'Acrobat.exe') AND (parent_process:explorer.exe OR cmd.exe) AND process_command_line:contains('.pdf')