CVE-2020-3801
📋 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 of vulnerable versions who open malicious PDF files 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 with attacker gaining full control over the victim's computer, potentially leading to data theft, ransomware deployment, or lateral movement within networks.
Likely Case
Malicious PDF files delivered via phishing emails or compromised websites lead to malware installation, credential theft, or system disruption.
If Mitigated
With proper patching and security controls, impact is limited to failed exploitation attempts that trigger security alerts.
🎯 Exploit Status
User interaction required (opening malicious PDF), but exploitation is straightforward once the vulnerability is triggered.
🛠️ 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: No
Instructions:
1. Open Adobe Acrobat or Reader. 2. Go to Help > Check for Updates. 3. Follow prompts to install available updates. 4. Alternatively, download and install latest version from Adobe website.
🔧 Temporary Workarounds
Disable JavaScript in Adobe Reader
allPrevents JavaScript-based exploitation vectors that might trigger the vulnerability
Edit > Preferences > JavaScript > Uncheck 'Enable Acrobat JavaScript'
Use Protected View
allOpen PDFs in protected mode to limit potential damage
File > Properties > Security > Enable Protected View for all files
🧯 If You Can't Patch
- Restrict PDF file handling to sandboxed environments or virtual machines
- Implement application whitelisting to block unauthorized executables from running
🔍 How to Verify
Check if Vulnerable:
Check Help > About Adobe Acrobat/Reader and compare version against affected rangesCheck Version:
On Windows: wmic product where name like "Adobe Acrobat%" get versionVerify Fix Applied:
Verify version is 2020.009.20063 or later, 2017.011.30166 or later, or 2015.006.30523 or later📡 Detection & Monitoring
Log Indicators:
- Adobe crash reports with memory access violations
- Windows Event Logs showing AcroRd32.exe crashes with exception codes like 0xC0000005
Network Indicators:
- Unusual outbound connections from Acrobat/Reader processes
- PDF downloads from suspicious sources
SIEM Query:
process_name:"AcroRd32.exe" AND event_id:1000 AND exception_code:0xC0000005