CVE-2023-41719: Ivanti Connect Secure RCE Vulnerability

CVE-2023-41719 Overview

CVE-2023-41719 is a remote code execution vulnerability affecting Ivanti Connect Secure, a widely deployed SSL VPN solution used by enterprises worldwide to provide secure remote access to corporate networks. This vulnerability allows an attacker who has successfully impersonated an administrator to craft a specific web request that leads to remote code execution on the affected appliance.

Ivanti Connect Secure (formerly Pulse Connect Secure) is a critical infrastructure component in many enterprise environments, serving as the gateway for remote workforce connectivity. The exploitation of this vulnerability requires administrative privileges, but successful exploitation grants attackers the ability to execute arbitrary code on the VPN appliance, potentially compromising the entire network perimeter security.

Critical Impact

Successful exploitation enables remote code execution on Ivanti Connect Secure appliances, potentially allowing attackers to compromise VPN infrastructure, intercept network traffic, and pivot to internal systems.

Affected Products

• Ivanti Connect Secure versions 9.1R1 through 9.1R18.3
• Ivanti Connect Secure versions 21.9R1 through 22.6R1
• All Ivanti Connect Secure versions below 22.6R2

Discovery Timeline

• December 14, 2023 - CVE-2023-41719 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2023-41719

Vulnerability Analysis

This vulnerability represents a significant security risk to organizations relying on Ivanti Connect Secure for their VPN infrastructure. The attack requires the threat actor to first gain or impersonate administrator-level access to the appliance's web management interface. Once this prerequisite is met, the attacker can craft specially formatted web requests that exploit improper handling of user-supplied input, ultimately leading to arbitrary code execution on the underlying system.

The network-accessible nature of VPN appliances makes this particularly concerning, as these devices are intentionally exposed to the internet to facilitate remote access. While the requirement for administrative privileges limits the immediate attack surface, organizations must consider scenarios where administrative credentials may have been compromised through phishing, credential stuffing, or other attack vectors.

Root Cause

The root cause of CVE-2023-41719 stems from insufficient validation of web requests processed by the administrative interface of Ivanti Connect Secure. The vulnerability allows specially crafted requests to bypass security controls and execute commands at the system level. The specific CWE classification is not publicly detailed by the vendor, but the vulnerability pattern suggests improper input validation or command injection issues within the web application framework.

Attack Vector

The attack is conducted over the network through the web management interface of Ivanti Connect Secure appliances. The exploitation flow involves:

1. An attacker establishes a position where they can impersonate or authenticate as an administrator to the appliance
2. The attacker crafts a malicious web request targeting vulnerable endpoints
3. The specially crafted request bypasses normal input validation
4. The payload executes with the privileges of the underlying system process
5. The attacker achieves remote code execution, potentially gaining full control of the appliance

Due to the sensitive nature of this vulnerability and its potential impact on critical infrastructure, detailed exploitation techniques are not publicly documented. Organizations should refer to the Ivanti Security Patch Release for technical guidance on identifying and remediating affected systems.

Detection Methods for CVE-2023-41719

Indicators of Compromise

• Unusual administrative session activity or login attempts from unexpected IP addresses
• Unexpected processes spawned by the Ivanti Connect Secure web server components
• Modified system files or new files created in application directories
• Anomalous outbound network connections from the VPN appliance

Detection Strategies

• Monitor administrative interface access logs for suspicious request patterns or unusual parameter values
• Implement SIEM rules to alert on administrative actions performed outside normal business hours or from untrusted networks
• Deploy network-based intrusion detection systems to analyze traffic to VPN appliance management interfaces
• Review appliance integrity using Ivanti's built-in integrity checking tools

Monitoring Recommendations

• Enable comprehensive logging on Ivanti Connect Secure appliances and forward logs to a centralized SIEM
• Configure alerts for multiple failed administrative login attempts followed by a successful authentication
• Monitor for configuration changes to the appliance that were not part of scheduled maintenance windows
• Implement behavioral analytics to detect anomalous administrative session patterns

How to Mitigate CVE-2023-41719

Immediate Actions Required

• Upgrade all Ivanti Connect Secure appliances to version 22.6R2 or later immediately
• Conduct a thorough review of administrative account access and reset credentials for all administrative users
• Audit recent administrative activity logs for signs of unauthorized access or suspicious requests
• Restrict administrative interface access to trusted management networks only

Patch Information

Ivanti has released version 22.6R2 of Connect Secure to address this vulnerability. Organizations should prioritize upgrading to this version or later releases. The security patch is documented in the Ivanti Security Patch Release article, which provides download links and upgrade instructions.

Workarounds

• Implement strict network access controls to limit administrative interface access to specific trusted IP addresses
• Enable multi-factor authentication for all administrative accounts to reduce the risk of credential compromise
• Deploy a web application firewall in front of management interfaces to filter potentially malicious requests
• Consider placing administrative interfaces on separate management VLANs accessible only through jump hosts

# Example: Restrict administrative access via firewall rules
# Limit admin interface (typically port 443) to management network only
iptables -A INPUT -p tcp --dport 443 -s 10.0.100.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP

# Verify current Ivanti Connect Secure version
# Access admin console -> System -> Platform -> Version information
# Ensure version is 22.6R2 or later