CVE-2025-58576
📋 TL;DR
A cross-site request forgery (CSRF) vulnerability in GroupSession collaboration software allows attackers to trick authenticated users into performing unintended actions. Users of GroupSession Free edition before 5.3.0, GroupSession byCloud before 5.3.3, and GroupSession ZION before 5.3.2 are affected when logged into vulnerable instances.
💻 Affected Systems
- GroupSession Free edition
- GroupSession byCloud
- GroupSession ZION
📦 What is this software?
Groupsession by Groupsession
Groupsession by Groupsession
Groupsession by Groupsession
⚠️ Risk & Real-World Impact
Worst Case
Attackers could manipulate user accounts to change settings, delete data, or perform administrative actions depending on the victim's privileges.
Likely Case
Attackers trick users into changing their own profile settings, posting unauthorized content, or performing limited actions within their permission scope.
If Mitigated
With proper CSRF protections, the attack fails as requests lack valid anti-CSRF tokens.
🎯 Exploit Status
Exploitation requires the victim to be authenticated and visit a malicious page while logged into GroupSession.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Free edition 5.3.0+, byCloud 5.3.3+, ZION 5.3.2+
Vendor Advisory: https://groupsession.jp/info/info-news/security20251208
Restart Required: Yes
Instructions:
1. Backup your GroupSession installation and database. 2. Download the patched version from the official vendor site. 3. Follow the vendor's upgrade instructions for your specific edition. 4. Restart the application server. 5. Verify the upgrade completed successfully.
🔧 Temporary Workarounds
Implement CSRF tokens manually
allAdd CSRF protection tokens to all state-changing requests if patching is delayed
Use SameSite cookie attribute
allConfigure session cookies with SameSite=Strict or SameSite=Lax to limit cross-origin requests
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to detect and block CSRF patterns
- Educate users about the risks of clicking unknown links while logged into business applications
🔍 How to Verify
Check if Vulnerable:
Check your GroupSession version in the administration panel or configuration files. Compare against affected versions.Check Version:
Check the admin dashboard or review the application's version file (location varies by installation)Verify Fix Applied:
After upgrading, verify the version number matches or exceeds the patched versions. Test that state-changing requests now require CSRF tokens.📡 Detection & Monitoring
Log Indicators:
- Multiple failed state-changing requests from same user in short time
- Requests missing expected CSRF tokens or referrer headers
Network Indicators:
- Unusual POST requests to GroupSession endpoints from unexpected referrers
SIEM Query:
source="groupsession" AND (http_method="POST" OR http_method="PUT" OR http_method="DELETE") AND NOT csrf_token=*