CVE-2021-39829
📋 TL;DR
This CVE describes an out-of-bounds write vulnerability in Adobe Framemaker that allows arbitrary code execution when a user opens a malicious PDF file. Attackers can exploit this to run code with the victim's privileges. Users of Adobe Framemaker versions 2019 Update 8 and earlier, and 2020 Release Update 2 and earlier are affected.
💻 Affected Systems
- Adobe Framemaker
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control of the victim's computer and potentially moving laterally through the network.
Likely Case
Local privilege escalation leading to data theft, ransomware deployment, or persistence establishment on the affected system.
If Mitigated
Limited impact with proper application sandboxing and user privilege restrictions, potentially resulting in application crash only.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious PDF). No public exploit code has been disclosed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Framemaker 2019 Update 9, Framemaker 2020 Release Update 3
Vendor Advisory: https://helpx.adobe.com/security/products/framemaker/apsb21-74.html
Restart Required: Yes
Instructions:
1. Open Adobe Framemaker. 2. Go to Help > Check for Updates. 3. Follow prompts to install available updates. 4. Restart Framemaker after installation completes.
🔧 Temporary Workarounds
Disable PDF file association
allPrevent Framemaker from automatically opening PDF files by changing file associations
Windows: Control Panel > Default Programs > Associate a file type or protocol with a program
macOS: Right-click PDF > Get Info > Open With > Change to different application
Application sandboxing
allRun Framemaker in restricted environment to limit potential damage
Windows: Use AppLocker or Windows Sandbox
macOS: Use sandbox-exec or create restricted user account
🧯 If You Can't Patch
- Implement application whitelisting to prevent unauthorized code execution
- Use network segmentation to isolate Framemaker systems from critical assets
🔍 How to Verify
Check if Vulnerable:
Check Framemaker version in Help > About Adobe Framemaker. If version is 2019 Update 8 or earlier, or 2020 Release Update 2 or earlier, system is vulnerable.Check Version:
Windows: wmic product where name="Adobe Framemaker" get version
macOS: /Applications/Adobe\ Framemaker\ 2020/Adobe\ Framemaker.app/Contents/MacOS/Adobe\ Framemaker --versionVerify Fix Applied:
Verify version is 2019 Update 9 or later, or 2020 Release Update 3 or later in Help > About Adobe Framemaker.📡 Detection & Monitoring
Log Indicators:
- Unexpected Framemaker crashes when opening PDF files
- Suspicious child processes spawned from Framemaker
- Unusual network connections from Framemaker process
Network Indicators:
- Outbound connections to suspicious IPs from Framemaker process
- DNS requests for known malicious domains from Framemaker
SIEM Query:
process_name:"framemaker.exe" AND (event_id:1 OR event_id:4688) AND parent_process_name NOT IN ("explorer.exe", "cmd.exe")