CVE-2024-22052: Ivanti Connect Secure DoS Vulnerability

CVE-2024-22052 Overview

CVE-2024-22052 is a null pointer dereference vulnerability affecting the IPSec component of Ivanti Connect Secure (versions 9.x and 22.x) and Ivanti Policy Secure. This vulnerability allows an unauthenticated malicious user to send specially crafted requests to crash the service, resulting in a Denial of Service (DoS) condition. The vulnerability requires no authentication and can be exploited remotely over the network.

Critical Impact

Unauthenticated remote attackers can cause service disruption by crashing the IPSec component, potentially affecting VPN availability for enterprise users relying on Ivanti secure access solutions.

Affected Products

• Ivanti Connect Secure versions 9.1 (R1 through R18) and 22.x (22.1 through 22.6)
• Ivanti Policy Secure versions 9.0, 9.1 (R1 through R18), and 22.x (22.1 through 22.6)

Discovery Timeline

• April 4, 2024 - CVE-2024-22052 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2024-22052

Vulnerability Analysis

This vulnerability stems from improper pointer handling within the IPSec component of Ivanti's secure access products. When the affected component receives a specially crafted network request, it fails to properly validate pointer references before dereferencing them. This results in a null pointer dereference condition that causes the service to crash unexpectedly.

The IPSec component is a critical part of the VPN infrastructure, handling secure tunnel establishment and encrypted communications. A crash in this component directly impacts the availability of VPN services, potentially disconnecting active users and preventing new connections until the service is restored.

This vulnerability is classified under CWE-476 (NULL Pointer Dereference) and CWE-703 (Improper Check or Handling of Exceptional Conditions), indicating both the specific technical flaw and the broader failure to properly handle exceptional input conditions.

Root Cause

The root cause of CVE-2024-22052 lies in insufficient validation of pointer references within the IPSec packet processing logic. When the component processes incoming IPSec-related requests, it assumes certain data structures will be properly initialized. A malformed request can trigger a code path where a pointer that should reference a valid memory location instead contains a null value. When this null pointer is subsequently dereferenced, the process terminates abnormally.

The vulnerability affects a broad range of versions across both Connect Secure and Policy Secure product lines, suggesting the flawed code has been present in the IPSec implementation for an extended period.

Attack Vector

The attack vector for this vulnerability is network-based and requires no authentication, making it particularly accessible to attackers. An adversary can exploit this vulnerability by:

1. Identifying an exposed Ivanti Connect Secure or Policy Secure gateway on the network
2. Crafting a malicious request targeting the IPSec component
3. Sending the malformed request to trigger the null pointer dereference
4. Causing the service to crash and become unavailable

The attack can be performed remotely without requiring any prior access to the target system, valid credentials, or user interaction. This makes the vulnerability attractive for attackers seeking to disrupt enterprise VPN services.

Detection Methods for CVE-2024-22052

Indicators of Compromise

• Unexpected crashes or restarts of the IPSec service on Ivanti Connect Secure or Policy Secure appliances
• Increased volume of malformed or anomalous traffic targeting IPSec-related ports
• Service availability gaps correlating with unusual network traffic patterns
• Error logs indicating null pointer exceptions or segmentation faults in the IPSec component

Detection Strategies

• Monitor Ivanti appliance system logs for service crash events, particularly those related to the IPSec component
• Implement network intrusion detection rules to identify malformed IPSec traffic patterns
• Configure alerting for unexpected service restarts on Ivanti gateways
• Use SentinelOne Singularity to monitor for anomalous process terminations and crash indicators on network appliances

Monitoring Recommendations

• Establish baseline metrics for IPSec service availability and alert on deviations
• Configure SNMP traps or syslog forwarding to capture service crash events in real-time
• Implement network traffic analysis to detect unusual patterns targeting Ivanti appliances
• Review Ivanti appliance health metrics regularly through the management console

How to Mitigate CVE-2024-22052

Immediate Actions Required

• Apply the latest security patches from Ivanti immediately for all affected Connect Secure and Policy Secure deployments
• Review the Ivanti Security Advisory for specific patch versions and upgrade instructions
• Inventory all Ivanti Connect Secure and Policy Secure instances to identify vulnerable deployments
• Implement network segmentation to limit direct exposure of Ivanti appliances to untrusted networks

Patch Information

Ivanti has released security patches addressing this vulnerability. Organizations should consult the official Ivanti Security Advisory for detailed patch information and supported upgrade paths. This advisory also covers related vulnerabilities CVE-2024-21894, CVE-2024-22053, and CVE-2024-22023, which should be addressed simultaneously.

Workarounds

• Restrict network access to Ivanti appliances using firewall rules to limit exposure to trusted IP ranges only
• Implement rate limiting on IPSec-related traffic to mitigate potential DoS attempts
• Enable enhanced logging to quickly detect exploitation attempts while awaiting patch deployment
• Consider deploying redundant Ivanti appliances to maintain availability during potential attacks

# Example: Restrict access to Ivanti appliance using iptables
# Replace 192.168.1.0/24 with your trusted network range
# Replace 10.0.0.50 with your Ivanti appliance IP

iptables -A INPUT -d 10.0.0.50 -s 192.168.1.0/24 -p udp --dport 500 -j ACCEPT
iptables -A INPUT -d 10.0.0.50 -s 192.168.1.0/24 -p udp --dport 4500 -j ACCEPT
iptables -A INPUT -d 10.0.0.50 -p udp --dport 500 -j DROP
iptables -A INPUT -d 10.0.0.50 -p udp --dport 4500 -j DROP