CVE-2025-21158
📋 TL;DR
An integer underflow vulnerability in Adobe InDesign allows arbitrary code execution when a user opens a malicious file. This affects users of InDesign Desktop versions ID20.0, ID19.5.1 and earlier. Successful exploitation gives attackers control over the victim's system with the same privileges as the current user.
💻 Affected Systems
- Adobe InDesign Desktop
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining complete control over the victim's computer, enabling data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Malicious actors craft specially designed InDesign files and distribute them via phishing or compromised websites, leading to targeted attacks against designers and publishing professionals.
If Mitigated
With proper patching and user awareness, impact is limited to isolated incidents where users ignore security warnings about untrusted files.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file). No public exploit code available at time of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to InDesign version 20.1 or later
Vendor Advisory: https://helpx.adobe.com/security/products/indesign/apsb25-01.html
Restart Required: No
Instructions:
1. Open Adobe Creative Cloud application. 2. Navigate to 'Apps' tab. 3. Find Adobe InDesign and click 'Update'. 4. Alternatively, download latest version from Adobe website.
🔧 Temporary Workarounds
Restrict InDesign file execution
allConfigure application control policies to block execution of InDesign files from untrusted sources
🧯 If You Can't Patch
- Implement application whitelisting to prevent execution of InDesign from untrusted locations
- Educate users to never open InDesign files from unknown or untrusted sources
🔍 How to Verify
Check if Vulnerable:
Check InDesign version via Help > About InDesign. If version is ID20.0, ID19.5.1 or earlier, system is vulnerable.Check Version:
On Windows: Check registry at HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\InDesign\[Version]\ProductVersion. On macOS: Check /Applications/Adobe InDesign [Version]/Adobe InDesign.app/Contents/Info.plistVerify Fix Applied:
Verify InDesign version is 20.1 or later via Help > About InDesign.📡 Detection & Monitoring
Log Indicators:
- Unexpected InDesign crashes with malformed files
- Process creation from InDesign with suspicious command lines
Network Indicators:
- Downloads of InDesign files from suspicious domains
- Outbound connections from InDesign process to unknown IPs
SIEM Query:
Process creation where parent_process contains 'indesign' and (command_line contains '.indd' or command_line contains '.indl')