CVE-2019-8055
📋 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 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 through arbitrary code execution with the privileges of the current user, potentially leading to data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Malicious PDF files delivered via phishing or compromised websites lead to system compromise, data exfiltration, or lateral movement within networks.
If Mitigated
With proper security controls, exploitation attempts are blocked by application sandboxing, memory protection mechanisms, or security software, limiting impact to application crashes.
🎯 Exploit Status
Exploitation requires user interaction (opening a malicious PDF) but no authentication. Use-after-free vulnerabilities typically require careful memory manipulation to achieve reliable code execution.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Acrobat DC/Reader DC: 2019.012.20036 and later; Acrobat 2017/Reader 2017: 2017.011.30144 and later; Acrobat 2015/Reader 2015: 2015.006.30499 and later
Vendor Advisory: https://helpx.adobe.com/security/products/acrobat/apsb19-41.html
Restart Required: No
Instructions:
1. Open Adobe Acrobat or Reader. 2. Navigate to Help > Check for Updates. 3. Follow prompts to download and install available updates. 4. Alternatively, download the latest version from Adobe's website and install it.
🔧 Temporary Workarounds
Disable JavaScript in Adobe Reader
allPrevents JavaScript-based exploitation vectors that might leverage this vulnerability
Edit > Preferences > JavaScript > Uncheck 'Enable Acrobat JavaScript'
Use Protected View
allOpens PDFs in a sandboxed environment that limits potential damage
File > Properties > Security > Enable Protected View for untrusted documents
🧯 If You Can't Patch
- Restrict PDF file handling to trusted sources only and implement application whitelisting to prevent unauthorized PDF viewers
- Deploy endpoint protection with memory protection capabilities and monitor for suspicious PDF-related process activity
🔍 How to Verify
Check if Vulnerable:
Check Adobe Acrobat/Reader version against affected version ranges. Vulnerable if version is at or below the thresholds listed in affected_systems.versionsCheck Version:
Windows: Open Adobe Acrobat/Reader > Help > About Adobe Acrobat/Reader; macOS: Adobe Acrobat/Reader > About Adobe Acrobat/ReaderVerify Fix Applied:
Verify Adobe Acrobat/Reader version is at or above the patch_version thresholds📡 Detection & Monitoring
Log Indicators:
- Adobe Acrobat/Reader crash logs with memory access violations
- Unexpected child processes spawned from Adobe Acrobat/Reader
- Unusual network connections originating from Adobe processes
Network Indicators:
- PDF downloads from untrusted sources followed by Adobe process anomalies
- Command and control traffic patterns following PDF file access
SIEM Query:
source="*adobe*" AND (event_type="crash" OR process_name="acrobat.exe" OR process_name="AcroRd32.exe") AND (memory_access_violation OR exception_code=0xc0000005)