CVE-2020-3792
📋 TL;DR
This CVE describes a use-after-free vulnerability in Adobe Acrobat and Reader that could allow attackers to execute arbitrary code on affected systems. Users who open malicious PDF files with vulnerable versions are at risk. The vulnerability affects multiple versions across different release tracks.
💻 Affected Systems
- Adobe Acrobat DC
- Adobe Acrobat Reader DC
- Adobe Acrobat 2017
- Adobe Acrobat Reader 2017
- Adobe Acrobat 2015
- Adobe Acrobat Reader 2015
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise through arbitrary code execution with the privileges of the user opening the malicious PDF, potentially leading to data theft, ransomware deployment, or lateral movement within networks.
Likely Case
Attackers trick users into opening malicious PDFs via phishing emails or compromised websites, leading to malware installation, credential theft, or system compromise.
If Mitigated
With proper patching and security controls, the risk is limited to isolated incidents where users bypass security measures to open untrusted PDFs.
🎯 Exploit Status
Exploitation requires user interaction to open a malicious PDF file. The use-after-free vulnerability requires specific memory manipulation techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2020.009.20063 for 2020 track, 2017.011.30166 for 2017 track, 2015.006.30523 for 2015 track
Vendor Advisory: https://helpx.adobe.com/security/products/acrobat/apsb20-13.html
Restart Required: Yes
Instructions:
1. Open Adobe Acrobat or Reader. 2. Navigate to Help > Check for Updates. 3. Follow prompts to download and 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 to trigger the vulnerability
Edit > Preferences > JavaScript > Uncheck 'Enable Acrobat JavaScript'
Use Protected View for untrusted files
allOpens PDFs in a sandboxed environment that limits potential damage
File > Properties > Security > Enable Protected View for files from potentially unsafe locations
🧯 If You Can't Patch
- Block PDF files at email gateways and web proxies
- Implement application whitelisting to prevent unauthorized executables from running
🔍 How to Verify
Check if Vulnerable:
Check Adobe Acrobat/Reader version via Help > About Adobe Acrobat/Reader and compare against affected versionsCheck Version:
On Windows: wmic product where "name like 'Adobe Acrobat%'" get versionVerify Fix Applied:
Verify version is 2020.009.20063 or later for 2020 track, 2017.011.30166 or later for 2017 track, or 2015.006.30523 or later for 2015 track📡 Detection & Monitoring
Log Indicators:
- Application crashes in Adobe Acrobat/Reader logs
- Unexpected process creation from Acrobat/Reader
- Memory access violations in system logs
Network Indicators:
- Outbound connections from Acrobat/Reader to suspicious IPs
- DNS requests for known malicious domains following PDF opening
SIEM Query:
source="*acrobat*" OR source="*reader*" AND (event_type="crash" OR process_name="cmd.exe" OR process_name="powershell.exe")