CVE-2020-9698
📋 TL;DR
This CVE describes a buffer overflow vulnerability in Adobe Acrobat and Reader that could allow attackers to execute arbitrary code on affected systems. Users running vulnerable versions of Adobe Acrobat or Reader are at risk when opening malicious PDF files. 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 of the affected system, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Local privilege escalation or remote code execution when a user opens a specially crafted malicious PDF file, leading to malware installation or data exfiltration.
If Mitigated
Limited impact with proper application sandboxing, least privilege principles, and network segmentation preventing lateral movement.
🎯 Exploit Status
Exploitation requires user interaction (opening a malicious PDF). No public exploit code was available at the time of the advisory, but buffer overflow vulnerabilities in PDF readers are commonly targeted.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Acrobat DC/Reader DC: 2020.009.20075 or later; Acrobat 2017/Reader 2017: 2017.011.30172 or later; Acrobat 2015/Reader 2015: 2015.006.30524 or later
Vendor Advisory: https://helpx.adobe.com/security/products/acrobat/apsb20-48.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 buffer overflow
Edit > Preferences > JavaScript > Uncheck 'Enable Acrobat JavaScript'
Use Protected View
allEnable Protected View for files from potentially unsafe locations
Edit > Preferences > Security (Enhanced) > Check 'Enable Protected View at startup' and configure file sources
🧯 If You Can't Patch
- Restrict PDF file handling to sandboxed environments or virtual machines
- Implement application whitelisting to prevent execution of unauthorized code
🔍 How to Verify
Check if Vulnerable:
Check Adobe Acrobat/Reader version via Help > About Adobe Acrobat/Reader and compare against affected versions listed in the advisoryCheck Version:
On Windows: wmic product where "name like 'Adobe Acrobat%' or name like 'Adobe Reader%'" get name, versionVerify Fix Applied:
Verify version is equal to or higher than the patched versions: 2020.009.20075+, 2020.001.30003+, 2017.011.30172+, or 2015.006.30524+📡 Detection & Monitoring
Log Indicators:
- Application crashes of acrobat.exe or AcroRd32.exe with exception codes like 0xC0000005 (ACCESS_VIOLATION)
- Unexpected child processes spawned from Adobe Reader/Acrobat
- Suspicious file writes or registry modifications from Adobe processes
Network Indicators:
- Outbound connections from Adobe processes to suspicious IPs or domains
- DNS requests for known malicious domains from systems running Adobe Reader/Acrobat
SIEM Query:
source="*" (process_name="acrobat.exe" OR process_name="AcroRd32.exe") AND (event_id="1000" OR exception_code="0xC0000005")