CVE-2024-20726
📋 TL;DR
This CVE describes an out-of-bounds write vulnerability in Adobe Acrobat Reader that could allow arbitrary code execution when a user opens a malicious PDF file. The vulnerability affects users running vulnerable versions of Acrobat Reader on Windows, macOS, and potentially other platforms. Successful exploitation requires user interaction to open a malicious file.
💻 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 the network.
Likely Case
Local privilege escalation leading to malware installation, credential theft, or data exfiltration from the affected system.
If Mitigated
Limited impact with proper application sandboxing, exploit mitigations, and user awareness preventing malicious file execution.
🎯 Exploit Status
Exploitation requires user interaction to open a malicious PDF file. The vulnerability is in memory corruption that could be leveraged for code execution.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to version 20.005.30554 or 23.008.20476 or 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 the prompts to download and install the latest version. 4. Restart the application when prompted.
🔧 Temporary Workarounds
Disable JavaScript in Adobe Reader
allDisabling JavaScript can prevent some exploitation vectors that rely on JavaScript execution within PDF files
Edit > Preferences > JavaScript > Uncheck 'Enable Acrobat JavaScript'
Use Protected View
allEnable Protected View for files from potentially unsafe locations to limit execution capabilities
Edit > Preferences > Security (Enhanced) > Enable Protected View for all files from potentially unsafe locations
🧯 If You Can't Patch
- Implement application whitelisting to prevent execution of unauthorized PDF readers
- Deploy endpoint detection and response (EDR) solutions to detect and block malicious PDF file execution
🔍 How to Verify
Check if Vulnerable:
Open Adobe Acrobat Reader, go to Help > About Adobe Acrobat Reader DC, and check if version is 20.005.30539 or earlier, or 23.008.20470 or earlierCheck Version:
On Windows: "C:\Program Files\Adobe\Acrobat Reader DC\Reader\AcroRd32.exe" /? (check output) or check in Help > AboutVerify Fix Applied:
After updating, verify version is 20.005.30554 or later, or 23.008.20476 or later📡 Detection & Monitoring
Log Indicators:
- Application crashes of AcroRd32.exe or Adobe Reader processes
- Unusual process creation from Adobe Reader
- Multiple failed attempts to open PDF files
Network Indicators:
- Outbound connections from Adobe Reader process to suspicious IPs
- DNS requests for known malicious domains from Adobe Reader
SIEM Query:
Process Creation where Image contains 'AcroRd32.exe' or 'AcroRd64.exe' followed by Network Connection events