CVE-2021-28591
📋 TL;DR
CVE-2021-28591 is an out-of-bounds write vulnerability in Adobe Illustrator that allows arbitrary code execution when a malicious file is opened. Attackers can exploit this to run code with the victim's privileges, requiring user interaction via opening a crafted file. Users of Adobe Illustrator versions 25.2.3 and earlier are affected.
💻 Affected Systems
- Adobe Illustrator
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control of the victim's computer, data theft, ransomware deployment, and 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 preventing system-wide compromise.
🎯 Exploit Status
Exploitation requires user to open malicious file. No authentication needed beyond file access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 25.3 or later
Vendor Advisory: https://helpx.adobe.com/security/products/illustrator/apsb21-42.html
Restart Required: Yes
Instructions:
1. Open Adobe Illustrator. 2. Go to Help > Updates. 3. Install available updates to version 25.3 or later. 4. Restart Illustrator after installation.
🔧 Temporary Workarounds
Disable Illustrator file associations
windowsPrevent automatic opening of Illustrator files by changing default file associations
Use application sandboxing
allRun Illustrator in restricted environment to limit potential damage
🧯 If You Can't Patch
- Implement application allowlisting to restrict which applications can run
- Use network segmentation to isolate Illustrator workstations from critical systems
🔍 How to Verify
Check if Vulnerable:
Check Illustrator version via Help > About Illustrator. If version is 25.2.3 or earlier, system is vulnerable.Check Version:
On Windows: Check registry at HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\Illustrator\25.0\Installer\VersionVerify Fix Applied:
Verify Illustrator version is 25.3 or later via Help > About Illustrator.📡 Detection & Monitoring
Log Indicators:
- Unexpected Illustrator crashes
- Suspicious file opens from untrusted sources
- Process creation from Illustrator with unusual parameters
Network Indicators:
- Outbound connections from Illustrator process to unknown IPs
- DNS requests for suspicious domains after file open
SIEM Query:
process_name="Illustrator.exe" AND (event_id=1000 OR event_id=1001) | where file_path contains suspicious_extension