CVE-2022-27789
📋 TL;DR
CVE-2022-27789 is a use-after-free vulnerability in Adobe Acrobat Reader DC's acroform event processing that could allow arbitrary code execution when a user opens a malicious PDF file. This affects users of Adobe Acrobat Reader DC versions 22.001.20085 and earlier, 20.005.3031x and earlier, and 17.012.30205 and earlier. Successful exploitation requires user interaction through opening a malicious file.
💻 Affected Systems
- Adobe Acrobat Reader DC
📦 What is this software?
Acrobat by Adobe
Acrobat by Adobe
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 code execution in the context of the current user, allowing file system access, credential theft, and installation of additional malware.
If Mitigated
Limited impact with proper application sandboxing and user privilege restrictions, potentially containing the exploit to the application context.
🎯 Exploit Status
Exploitation requires user interaction (opening a malicious PDF). The use-after-free vulnerability requires precise timing and memory manipulation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 22.001.20085 (for continuous track), 20.005.30314 (for 2020 classic track), 17.012.30206 (for 2017 classic track)
Vendor Advisory: https://helpx.adobe.com/security/products/acrobat/apsb22-16.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 and install the latest version from Adobe's website.
🔧 Temporary Workarounds
Disable JavaScript in Adobe Reader
allPrevents JavaScript execution 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 > Open > Select 'Protected View' option when opening untrusted files
🧯 If You Can't Patch
- Implement application whitelisting to block unauthorized PDF readers
- Use network segmentation to isolate PDF processing workstations
- Deploy endpoint detection and response (EDR) solutions to monitor for exploitation attempts
- Educate users about the risks of opening untrusted PDF files
🔍 How to Verify
Check if Vulnerable:
Check Adobe Acrobat Reader DC version via Help > About Adobe Acrobat Reader DCCheck Version:
On Windows: wmic product where "name like 'Adobe Acrobat Reader DC%'" get versionVerify Fix Applied:
Verify version is 22.001.20085 or higher (continuous track), 20.005.30314 or higher (2020 classic), or 17.012.30206 or higher (2017 classic)📡 Detection & Monitoring
Log Indicators:
- Adobe Reader crash logs with memory access violations
- Unexpected child processes spawned from acroRd32.exe
- Suspicious file access patterns from Adobe Reader process
Network Indicators:
- Outbound connections from Adobe Reader to unexpected destinations
- DNS requests for known malicious domains from PDF reader process
SIEM Query:
process_name:acroRd32.exe AND (event_id:1 OR parent_process_name:explorer.exe) AND command_line:*pdf