CVE-2020-3754
📋 TL;DR
This CVE describes a buffer error vulnerability in Adobe Acrobat and Reader that could allow attackers to execute arbitrary code on affected systems. The vulnerability affects multiple versions of Adobe's PDF software across different release tracks. Users who open malicious PDF files with vulnerable versions are at risk.
💻 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 affected system, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Malicious PDF files delivered via phishing or compromised websites lead to malware installation, credential theft, or data exfiltration from the affected system.
If Mitigated
With proper patching and security controls, the impact is limited to isolated incidents that can be quickly contained and remediated.
🎯 Exploit Status
Exploitation requires user interaction (opening a malicious PDF file). The buffer error vulnerability type (CWE-119) typically has relatively low exploitation complexity once the specific flaw is understood.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Acrobat DC/Reader DC: 2020.001.20002 or later; Acrobat 2017/Reader 2017: 2020.001.20002 or later; Acrobat 2015/Reader 2015: 2020.001.20002 or later
Vendor Advisory: https://helpx.adobe.com/security/products/acrobat/apsb20-05.html
Restart Required: Yes
Instructions:
1. Open Adobe Acrobat or Reader. 2. Go to Help > Check for Updates. 3. Follow the prompts to download and install available updates. 4. Restart the application when prompted. 5. Verify the update by checking Help > About Adobe Acrobat/Reader.
🔧 Temporary Workarounds
Disable JavaScript in Adobe Reader
allDisabling JavaScript can prevent some exploitation vectors that rely on JavaScript to trigger the vulnerability
Edit > Preferences > JavaScript > Uncheck 'Enable Acrobat JavaScript'
Use Protected View
allConfigure Adobe Reader to open all PDFs in Protected View mode to limit potential damage
Edit > Preferences > Security (Enhanced) > Check 'Enable Protected View at startup' and 'Enable Enhanced Security'
🧯 If You Can't Patch
- Block PDF files at network perimeter using content filtering or email gateways
- Use application whitelisting to prevent execution of unauthorized processes from Adobe Reader
🔍 How to Verify
Check if Vulnerable:
Check Adobe Acrobat/Reader version via Help > About Adobe Acrobat/Reader and compare against affected version rangesCheck Version:
On Windows: wmic product where "name like 'Adobe Acrobat%' or name like 'Adobe Reader%'" get name, versionVerify Fix Applied:
Verify version is 2020.001.20002 or later and ensure automatic updates are enabled📡 Detection & Monitoring
Log Indicators:
- Adobe Acrobat/Reader crash logs with memory access violations
- Windows Event Logs showing application crashes (Event ID 1000)
- Unexpected child processes spawned from Adobe Reader
Network Indicators:
- Outbound connections from Adobe Reader to suspicious IPs
- DNS requests for known malicious domains following PDF file opening
SIEM Query:
source="windows" AND (event_id=1000 OR event_id=1001) AND process_name="AcroRd32.exe" OR process_name="Acrobat.exe"