CVE-2024-38649
📋 TL;DR
This vulnerability allows remote unauthenticated attackers to trigger an out-of-bounds write in the IPsec component of Ivanti Connect Secure, potentially causing denial of service. It affects Ivanti Connect Secure versions before 22.7R2.1, excluding the 9.1Rx branch. Attackers can exploit this without authentication.
💻 Affected Systems
- Ivanti Connect Secure
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system crash or service disruption of the Ivanti Connect Secure gateway, potentially affecting all VPN/remote access services.
Likely Case
Service disruption or instability of the IPsec VPN component, impacting remote access capabilities.
If Mitigated
Limited impact if proper network segmentation and access controls prevent unauthenticated access to vulnerable services.
🎯 Exploit Status
Out-of-bounds write vulnerabilities in network services often lead to reliable DoS conditions and may potentially enable more severe exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 22.7R2.1 or later
Vendor Advisory: https://forums.ivanti.com/s/article/Security-Advisory-Ivanti-Connect-Secure-ICS-Ivanti-Policy-Secure-IPS-Ivanti-Secure-Access-Client-ISAC-Multiple-CVEs
Restart Required: Yes
Instructions:
1. Download the patch from Ivanti support portal. 2. Backup current configuration. 3. Apply the patch following Ivanti's upgrade documentation. 4. Reboot the appliance. 5. Verify successful upgrade and functionality.
🔧 Temporary Workarounds
Disable IPsec VPN
allTemporarily disable IPsec VPN services if not required, forcing users to alternative access methods like SSL VPN.
Network Access Restrictions
allImplement firewall rules to restrict access to IPsec services (UDP 500, 4500) to trusted IP ranges only.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate vulnerable systems from untrusted networks.
- Deploy intrusion prevention systems (IPS) with signatures for Ivanti Connect Secure vulnerabilities to detect and block exploitation attempts.
🔍 How to Verify
Check if Vulnerable:
Check the appliance version via web admin interface or CLI. If version is below 22.7R2.1 and not 9.1Rx, the system is vulnerable.Check Version:
ssh admin@<appliance-ip> 'show version' or check via web admin interface under System > Maintenance > VersionVerify Fix Applied:
Verify the version shows 22.7R2.1 or higher after patching and test IPsec VPN functionality.📡 Detection & Monitoring
Log Indicators:
- Unusual IPsec connection attempts from unknown sources
- IPsec service crashes or restarts
- High volume of malformed IPsec packets
Network Indicators:
- Unusual traffic patterns to UDP ports 500/4500
- IPsec protocol anomalies
- Connection attempts from unexpected geolocations
SIEM Query:
source="ivanti-connect-secure" AND (event_type="ipsec_error" OR event_type="service_crash")