CVE-2021-42725
📋 TL;DR
This vulnerability allows attackers to execute arbitrary code on systems running vulnerable versions of Adobe Bridge by tricking users into opening a malicious M4A audio file. The vulnerability affects Adobe Bridge 11.1.1 and earlier versions, putting users who process multimedia files at risk.
💻 Affected Systems
- Adobe Bridge
📦 What is this software?
Bridge 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
Local privilege escalation leading to malware installation, data exfiltration, or persistence mechanisms being established on the compromised system.
If Mitigated
Limited impact with proper application sandboxing and user privilege restrictions, potentially resulting in application crash rather than code execution.
🎯 Exploit Status
Requires user interaction to open malicious file. Memory corruption vulnerabilities in media parsers are commonly exploited.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 11.1.2 or later
Vendor Advisory: https://helpx.adobe.com/security/products/bridge/apsb21-94.html
Restart Required: Yes
Instructions:
1. Open Adobe Bridge. 2. Go to Help > Check for Updates. 3. Follow prompts to install Bridge 11.1.2 or later. 4. Restart the application.
🔧 Temporary Workarounds
Disable M4A file association
windowsRemove Adobe Bridge as default handler for M4A files to prevent automatic opening
Windows: Control Panel > Default Programs > Associate a file type or protocol with a program > Change .m4a to another application
Application sandboxing
allRun Adobe Bridge with reduced privileges using application sandboxing tools
🧯 If You Can't Patch
- Restrict user privileges to standard user accounts (not administrator)
- Implement application whitelisting to prevent execution of unauthorized code
🔍 How to Verify
Check if Vulnerable:
Check Adobe Bridge version in Help > About Adobe BridgeCheck Version:
Windows: "C:\Program Files\Adobe\Adobe Bridge 2021\Bridge.exe" --version (path may vary)Verify Fix Applied:
Verify version is 11.1.2 or later in Help > About Adobe Bridge📡 Detection & Monitoring
Log Indicators:
- Application crashes with memory access violations
- Unexpected child processes spawned from Bridge.exe
Network Indicators:
- Unexpected outbound connections from Adobe Bridge process
SIEM Query:
process_name:"Bridge.exe" AND (event_id:1000 OR event_id:1001) OR parent_process:"Bridge.exe" AND process_creation