CVE-2023-26405
📋 TL;DR
This vulnerability in Adobe Acrobat Reader allows attackers to execute arbitrary code on a victim's system when they open a malicious PDF file. It affects users of Adobe Acrobat Reader DC and Adobe Acrobat Reader 2020 on all supported platforms. The attacker needs to trick the user into opening a specially crafted file.
💻 Affected Systems
- Adobe Acrobat Reader DC
- Adobe Acrobat Reader 2020
📦 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 persistent backdoor installation.
Likely Case
Malware installation leading to credential theft, data exfiltration, or system disruption.
If Mitigated
No impact if users only open trusted PDF files from verified sources.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file). No public exploit code known at time of advisory.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: DC: 23.001.20174 or later; 2020: 20.005.30473 or later
Vendor Advisory: https://helpx.adobe.com/security/products/acrobat/apsb23-24.html
Restart Required: Yes
Instructions:
1. Open Adobe Acrobat Reader. 2. Go to Help > Check for Updates. 3. Follow prompts to install latest version. 4. Restart computer after installation.
🔧 Temporary Workarounds
Disable JavaScript in Adobe Reader
allPrevents JavaScript-based exploitation vectors
Edit > Preferences > JavaScript > Uncheck 'Enable Acrobat JavaScript'
Use Protected View
allOpen untrusted PDFs in sandboxed Protected View mode
File > Open > Select 'Protected View' option
🧯 If You Can't Patch
- Block PDF files from untrusted sources at email/web gateways
- Implement application whitelisting to prevent unauthorized executables
🔍 How to Verify
Check if Vulnerable:
Check Adobe Reader version in Help > About Adobe Acrobat Reader DCCheck Version:
Windows: wmic product where name="Adobe Acrobat Reader DC" get version; macOS: /Applications/Adobe\ Acrobat\ Reader\ DC.app/Contents/Info.plist | grep -A1 CFBundleShortVersionStringVerify Fix Applied:
Verify version is 23.001.20174 or later for DC, or 20.005.30473 or later for 2020 edition📡 Detection & Monitoring
Log Indicators:
- Adobe Reader crash logs with suspicious file paths
- Windows Event Logs showing unexpected process creation from AcroRd32.exe
Network Indicators:
- Outbound connections from Adobe Reader process to unknown IPs
- DNS requests for suspicious domains after PDF opening
SIEM Query:
process_name:"AcroRd32.exe" AND (parent_process:"explorer.exe" OR cmdline:"*.pdf") AND (process_creation OR network_connection)