CVE-2023-42820
📋 TL;DR
This vulnerability in JumpServer exposes the random number seed via API, allowing attackers to predict or replay verification codes used for password resets. This could enable unauthorized password resets for users with local authentication and without MFA enabled. Only affects JumpServer instances with local authentication users who don't have MFA enabled.
💻 Affected Systems
- JumpServer
📦 What is this software?
Jumpserver by Fit2cloud
Jumpserver by Fit2cloud
⚠️ Risk & Real-World Impact
Worst Case
Attackers could reset passwords for administrative accounts, gaining full control over the JumpServer instance and potentially accessing all managed systems.
Likely Case
Attackers could reset passwords for regular user accounts, gaining unauthorized access to systems managed through JumpServer.
If Mitigated
With MFA enabled or using external authentication, the vulnerability has no impact as verification codes cannot be used for authentication.
🎯 Exploit Status
Exploitation requires API access and understanding of the random seed exposure. No public exploits available at advisory time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.28.19 or 3.6.5
Vendor Advisory: https://github.com/jumpserver/jumpserver/security/advisories/GHSA-7prv-g565-82qp
Restart Required: Yes
Instructions:
1. Backup your JumpServer configuration and database. 2. Stop JumpServer services. 3. Upgrade to version 2.28.19 (for v2.x) or 3.6.5 (for v3.x). 4. Restart JumpServer services. 5. Verify the upgrade was successful.
🔧 Temporary Workarounds
Enable MFA for all users
allEnable Multi-Factor Authentication for all local authentication users to prevent exploitation
Use JumpServer admin interface to enable MFA for all users
Switch to external authentication
allMigrate users from local authentication to external authentication providers (LDAP, OAuth, etc.)
Configure external authentication in JumpServer settings
🧯 If You Can't Patch
- Enable MFA for all local authentication users immediately
- Restrict API access to trusted IP addresses only
🔍 How to Verify
Check if Vulnerable:
Check JumpServer version via web interface or by running 'jumpserver --version' commandCheck Version:
jumpserver --versionVerify Fix Applied:
Verify version is 2.28.19 or higher (for v2.x) or 3.6.5 or higher (for v3.x)📡 Detection & Monitoring
Log Indicators:
- Multiple failed password reset attempts
- Unusual API calls to verification code endpoints
- Password reset requests from unexpected IPs
Network Indicators:
- Unusual API traffic patterns to /api/v1/authentication/ endpoints
SIEM Query:
source="jumpserver" AND (event_type="password_reset" OR api_endpoint="*authentication*")🔗 References
- https://github.com/jumpserver/jumpserver/commit/42337f0d00b2a8d45ef063eb5b7deeef81597da5
- https://github.com/jumpserver/jumpserver/security/advisories/GHSA-7prv-g565-82qp
- https://github.com/jumpserver/jumpserver/commit/42337f0d00b2a8d45ef063eb5b7deeef81597da5
- https://github.com/jumpserver/jumpserver/security/advisories/GHSA-7prv-g565-82qp
