CVE-2020-24437
📋 TL;DR
This CVE describes a use-after-free vulnerability in Adobe Acrobat Reader DC that could allow arbitrary code execution when processing malicious PDF files. Attackers can exploit this by tricking users into opening specially crafted documents, potentially gaining control of the affected system. Users of vulnerable Adobe Acrobat Reader DC versions are affected.
💻 Affected Systems
- Adobe Acrobat Reader DC
📦 What is this software?
Acrobat by Adobe
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining the same privileges as the current user, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Malicious actor executes arbitrary code in user context, potentially stealing credentials, installing malware, or accessing sensitive documents.
If Mitigated
With proper patching and security controls, impact is limited to potential application crash or denial of service.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file). No public exploit code was found in initial research, but vulnerability is rated with CVSS 7.8 indicating significant risk.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2020.012.20056, 2020.001.30006, 2017.011.30176 or later
Vendor Advisory: https://helpx.adobe.com/security/products/acrobat/apsb20-67.html
Restart Required: Yes
Instructions:
1. Open Adobe Acrobat Reader DC. 2. Go to Help > Check for Updates. 3. Follow prompts to install available updates. 4. Restart the application. Alternatively, download latest version from Adobe website.
🔧 Temporary Workarounds
Disable JavaScript in Adobe Reader
allPrevents execution of JavaScript in PDF files which may mitigate some exploitation vectors
Edit > Preferences > JavaScript > Uncheck 'Enable Acrobat JavaScript'
Use Protected View
allOpen untrusted PDFs in Protected View mode to limit potential damage
File > Properties > Security > Enable Protected View for untrusted documents
🧯 If You Can't Patch
- Implement application whitelisting to block execution of unauthorized PDF readers
- Deploy endpoint protection with behavioral analysis to detect exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check Adobe Reader version via Help > About Adobe Acrobat Reader DC and compare with affected versionsCheck Version:
On Windows: wmic product where name="Adobe Acrobat Reader DC" get versionVerify Fix Applied:
Verify version is 2020.012.20056+, 2020.001.30006+, or 2017.011.30176+📡 Detection & Monitoring
Log Indicators:
- Adobe Reader crash logs with exception codes
- Windows Event Logs showing unexpected process termination
Network Indicators:
- Unexpected outbound connections from Adobe Reader process
- Downloads of PDF files from untrusted sources
SIEM Query:
source="*adobe*" AND (event_type="crash" OR exception_code="*" OR process_termination="unexpected")