CVE-2025-56527
📋 TL;DR
CVE-2025-56527 allows attackers to steal plaintext passwords stored in the client's localStorage in Kotaemon 0.11.0. This affects all users of the vulnerable version who store credentials in the application. Attackers can access these credentials through cross-site scripting or by compromising the client device.
💻 Affected Systems
- Kotaemon
📦 What is this software?
Kotaemon by Cinnamon
⚠️ Risk & Real-World Impact
Worst Case
Complete account takeover and credential theft leading to unauthorized access to sensitive systems and data exfiltration.
Likely Case
Credential theft from compromised client devices or through XSS attacks, enabling unauthorized access to the Kotaemon application.
If Mitigated
Limited impact if strong access controls, network segmentation, and client-side security measures are implemented.
🎯 Exploit Status
Exploitation requires access to client localStorage via XSS or physical/remote device compromise.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in commit 37cdc28
Vendor Advisory: https://github.com/Cinnamon/kotaemon/commit/37cdc28
Restart Required: Yes
Instructions:
1. Update Kotaemon to the latest version. 2. Restart the application. 3. Clear localStorage on all client devices. 4. Reset all stored passwords.
🔧 Temporary Workarounds
Disable localStorage Password Storage
allModify application configuration to prevent password storage in localStorage.
Modify application source code to remove localStorage.setItem() calls for passwords
Implement Client-Side Encryption
allAdd encryption layer for passwords before storing in localStorage.
Implement client-side encryption using Web Crypto API before localStorage.setItem()
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) to prevent XSS attacks
- Use browser extensions to block localStorage access for the application domain
🔍 How to Verify
Check if Vulnerable:
Inspect browser developer tools localStorage for plaintext passwords when using Kotaemon 0.11.0.Check Version:
Check application version in UI or package.json fileVerify Fix Applied:
Confirm passwords are no longer stored in plaintext in localStorage after update.📡 Detection & Monitoring
Log Indicators:
- Unusual authentication patterns
- Multiple failed login attempts from new locations
Network Indicators:
- Unexpected data exfiltration to external domains
- Suspicious JavaScript execution patterns
SIEM Query:
source="browser" AND event="localStorage_access" AND data="password"🔗 References
- https://github.com/Cinnamon/kotaemon
- https://github.com/Cinnamon/kotaemon/commit/37cdc28
- https://github.com/HanTul/Kotaemon-CVE-2025-56526-56527-disclosure
- https://harvest-sink-590.notion.site/Stored-XSS-via-Unsanitized-PDF-Content-Rendering-and-Plaintext-Credential-Exposure-in-LocalStorage-236770c3fe1e80f6a1aef381fb1c8f73
- https://skinny-exoplanet-584.notion.site/Stored-XSS-via-Unsanitized-PDF-Content-Rendering-and-Plaintext-Credential-Exposure-in-LocalStorage-22cd1563bd3380458588eb49f361a363?pvs=74
