CVE-2025-57740
📋 TL;DR
A heap-based buffer overflow vulnerability in Fortinet's FortiOS, FortiPAM, and FortiProxy allows authenticated users to execute arbitrary code via crafted RDP bookmark connection requests. This affects multiple versions across all three products, potentially enabling attackers to gain control of affected systems.
💻 Affected Systems
- FortiOS
- FortiPAM
- FortiProxy
📦 What is this software?
Fortios by Fortinet
Fortios by Fortinet
Fortios by Fortinet
Fortipam by Fortinet
Fortipam by Fortinet
Fortiproxy by Fortinet
Fortiproxy by Fortinet
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with root/admin privileges, enabling persistent access, data exfiltration, and lateral movement within the network.
Likely Case
Authenticated attackers gaining elevated privileges and executing malicious code on vulnerable systems, potentially leading to data theft or system disruption.
If Mitigated
Limited impact due to network segmentation, strong authentication controls, and monitoring preventing successful exploitation.
🎯 Exploit Status
Requires authenticated access and knowledge of RDP bookmark functionality. Heap-based overflows can be challenging to exploit reliably.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: FortiOS 7.6.3+, 7.4.8+, 7.2.11+, 7.0.15+, 6.4.16+; FortiPAM 1.5.1+, 1.4.3+; FortiProxy 7.6.3+, 7.4.4+, 7.2.9+, 7.0.15+
Vendor Advisory: https://fortiguard.fortinet.com/psirt/FG-IR-25-756
Restart Required: Yes
Instructions:
1. Backup current configuration. 2. Download appropriate firmware from Fortinet support portal. 3. Upload firmware to device via web GUI or CLI. 4. Install update following vendor instructions. 5. Reboot device. 6. Verify version and functionality.
🔧 Temporary Workarounds
Disable RDP bookmark connections
allTemporarily disable RDP bookmark functionality to prevent exploitation.
config system rdp-bookmark
set status disable
end
Restrict access to RDP features
allLimit which users/groups can access RDP bookmark functionality.
config user group
edit <group_name>
unset rdp-access
end
🧯 If You Can't Patch
- Implement strict network segmentation to isolate vulnerable devices from critical systems
- Enforce multi-factor authentication and least privilege access controls for all user accounts
🔍 How to Verify
Check if Vulnerable:
Check current firmware version via CLI: 'get system status' or web GUI System > Dashboard. Compare against affected versions list.Check Version:
get system status | grep VersionVerify Fix Applied:
Verify version is updated to patched version and test RDP bookmark functionality remains operational.📡 Detection & Monitoring
Log Indicators:
- Unusual RDP connection attempts
- Multiple failed authentication attempts followed by RDP access
- Process creation from unexpected sources
Network Indicators:
- Abnormal RDP traffic patterns to Fortinet devices
- Unexpected outbound connections from Fortinet devices
SIEM Query:
source="fortinet" AND (event_type="rdp" OR event_type="bookmark") AND (user!="admin" OR src_ip!="trusted_network")