CVE-2023-38043: Ivanti Secure Access Client DoS Vulnerability

CVE-2023-38043 Overview

A vulnerability exists in all versions of the Ivanti Secure Access Client below 22.6R1.1, which could allow a locally authenticated attacker to exploit a vulnerable configuration. This vulnerability potentially leads to a denial of service (DoS) condition on the user machine and, in some cases, can result in a full compromise of the system through privilege escalation.

Critical Impact

A locally authenticated attacker can exploit this vulnerability to cause denial of service conditions and potentially achieve full system compromise with elevated privileges on Windows systems running vulnerable Ivanti Secure Access Client versions.

Affected Products

• Ivanti Secure Access Client versions prior to 22.6R1.1
• Ivanti Secure Access Client version 22.6R1 (unpatched)
• Microsoft Windows operating systems running vulnerable Ivanti Secure Access Client

Discovery Timeline

• 2023-11-15 - CVE-2023-38043 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-38043

Vulnerability Analysis

This vulnerability in Ivanti Secure Access Client stems from improper resource management and configuration handling that can be exploited by local attackers. According to security research published by Northwave Cybersecurity, the vulnerability involves an arbitrary kernel function call mechanism within the Ivanti Secure Access Client, which can be leveraged by authenticated local users to manipulate system operations.

The vulnerability affects the Windows implementation of the Ivanti Secure Access Client and requires local authentication to exploit. Once exploited, an attacker can cause resource exhaustion leading to denial of service, and under certain conditions, escalate privileges to gain full control over the affected system. The local attack vector means that an attacker must already have some level of access to the target system, but the low complexity of exploitation combined with the potential for complete system compromise makes this a significant security concern for enterprise environments.

Root Cause

The root cause of this vulnerability relates to improper resource consumption (CWE-400) within the Ivanti Secure Access Client. The vulnerable configuration allows local users to trigger conditions that lead to resource exhaustion or manipulation of kernel-level operations. This design flaw enables attackers to exceed intended resource limits or invoke privileged functions through the client application's interfaces.

Attack Vector

The attack requires local access to the system with basic authentication. An attacker with local user privileges can exploit vulnerable configurations within the Ivanti Secure Access Client to trigger a denial of service condition or, in certain scenarios, escalate privileges to gain complete system control. The exploitation does not require user interaction beyond the initial local access.

The attack flow typically involves:

1. Gaining local access to a Windows system with Ivanti Secure Access Client installed
2. Identifying and exploiting the vulnerable configuration in client versions below 22.6R1.1
3. Triggering the vulnerability to cause denial of service or privilege escalation
4. In successful exploitation scenarios, achieving full system compromise

For detailed technical analysis of the arbitrary kernel function call mechanism, refer to the Northwave Cybersecurity Vulnerability Notice.

Detection Methods for CVE-2023-38043

Indicators of Compromise

• Unexpected crashes or service interruptions of the Ivanti Secure Access Client on Windows endpoints
• Unusual resource consumption patterns by IvantiSecureAccessClient processes
• Abnormal kernel-level activity originating from the Ivanti client processes
• Evidence of privilege escalation attempts on systems running vulnerable Ivanti client versions

Detection Strategies

• Implement endpoint detection rules to monitor for abnormal behavior from Ivanti Secure Access Client processes
• Deploy SentinelOne's behavioral AI to detect exploitation attempts targeting the vulnerable client
• Configure alerts for unusual resource consumption or process behavior associated with Ivanti client components
• Monitor for privilege escalation indicators on endpoints with vulnerable Ivanti client installations

Monitoring Recommendations

• Conduct regular software inventory audits to identify systems running Ivanti Secure Access Client versions below 22.6R1.1
• Enable detailed logging for Ivanti Secure Access Client activities across enterprise endpoints
• Leverage SentinelOne Singularity platform for real-time visibility into endpoint security posture and vulnerability status
• Monitor Windows event logs for suspicious activity related to local privilege escalation attempts

How to Mitigate CVE-2023-38043

Immediate Actions Required

• Upgrade Ivanti Secure Access Client to version 22.6R1.1 or later on all affected Windows systems
• Audit all endpoints for vulnerable Ivanti Secure Access Client installations
• Apply the principle of least privilege to limit the impact of potential local exploitation
• Temporarily restrict local access to critical systems if immediate patching is not feasible

Patch Information

Ivanti has released security fixes in Ivanti Secure Access Client version 22.6R1.1 that address this vulnerability. Organizations should prioritize upgrading all affected installations to this version or later. For detailed information about the security fixes, refer to the Ivanti Security Client Release Notes.

Workarounds

• Restrict local user access on systems where immediate patching is not possible
• Implement application control policies to monitor and restrict Ivanti client behavior
• Utilize SentinelOne's application vulnerability assessment to track remediation progress
• Consider temporary removal of the vulnerable client from high-risk systems until patching is complete

# Verify Ivanti Secure Access Client version on Windows systems
# Check installed version via PowerShell
Get-WmiObject -Class Win32_Product | Where-Object { $_.Name -like "*Ivanti Secure Access*" } | Select-Object Name, Version

# Alternative method using registry
Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\*" | Where-Object { $_.DisplayName -like "*Ivanti Secure Access*" } | Select-Object DisplayName, DisplayVersion