CVE-2024-21893: Ivanti Connect Secure SSRF Vulnerability

CVE-2024-21893 Overview

CVE-2024-21893 is a Server-Side Request Forgery (SSRF) vulnerability affecting the SAML component of Ivanti Connect Secure, Ivanti Policy Secure, and Ivanti Neurons for Zero-Trust Access. This vulnerability allows an unauthenticated attacker to access certain restricted resources without authentication by manipulating server-side requests through the SAML authentication mechanism. Given that these products are enterprise VPN and network access control solutions, successful exploitation can provide attackers with initial access to protected corporate networks and sensitive internal resources.

Critical Impact

This vulnerability is actively exploited in the wild and has been added to CISA's Known Exploited Vulnerabilities (KEV) catalog. The SSRF flaw in the SAML component allows unauthenticated attackers to bypass authentication and access internal resources, potentially enabling lateral movement within enterprise networks.

Affected Products

• Ivanti Connect Secure (versions 9.x and 22.x)
• Ivanti Policy Secure (versions 9.x and 22.x)
• Ivanti Neurons for Zero-Trust Access (versions 22.x)

Discovery Timeline

• January 31, 2024 - CVE-2024-21893 published to NVD
• October 30, 2025 - Last updated in NVD database

Technical Details for CVE-2024-21893

Vulnerability Analysis

The vulnerability resides within the SAML (Security Assertion Markup Language) authentication component used by Ivanti's network access products. SAML is a widely-adopted standard for exchanging authentication and authorization data between identity providers and service providers. The flaw allows attackers to craft malicious requests that cause the vulnerable server to make unintended outbound requests to arbitrary destinations, effectively turning the Ivanti appliance into a proxy for accessing internal resources.

This SSRF vulnerability is particularly dangerous because it exists in a pre-authentication context within the SAML processing flow. Attackers do not need valid credentials to exploit this vulnerability, making it an attractive target for initial access operations. When successfully exploited, the server processes attacker-controlled input that specifies internal network locations, allowing the attacker to reach resources that would otherwise be protected by network segmentation.

The vulnerability affects all major Ivanti network access products, including Connect Secure (versions 9.0 through 22.6), Policy Secure (versions 9.0 through 22.6), and Neurons for Zero-Trust Access (version 22.x), indicating a shared codebase vulnerability in the SAML handling logic across the product line.

Root Cause

The root cause of CVE-2024-21893 is improper input validation in the SAML component's request processing logic. The vulnerability is classified under CWE-918 (Server-Side Request Forgery), which occurs when an application fetches remote resources based on user-supplied input without adequately validating or sanitizing the destination URL. In this case, the SAML component fails to properly restrict or validate URLs within SAML messages, allowing attackers to specify arbitrary internal or external destinations for server-side requests.

Attack Vector

The attack vector for this vulnerability is network-based and requires no authentication or user interaction. An attacker can exploit this vulnerability by sending specially crafted SAML requests to the vulnerable Ivanti appliance. The attack flow typically involves:

1. The attacker identifies an Internet-exposed Ivanti Connect Secure, Policy Secure, or Neurons for ZTA endpoint
2. The attacker crafts a malicious SAML request containing URLs pointing to internal resources or metadata services
3. The SAML component processes the request and initiates server-side requests to the attacker-specified destinations
4. The server returns the response data to the attacker, disclosing internal resource contents or enabling further exploitation

This SSRF vulnerability can be leveraged to access internal services, cloud provider metadata endpoints (such as AWS IMDSv1), or to chain with other vulnerabilities for more severe impact including remote code execution.

Detection Methods for CVE-2024-21893

Indicators of Compromise

• Unusual outbound connections from Ivanti appliances to internal IP ranges or cloud metadata services (e.g., 169.254.169.254)
• Anomalous SAML authentication requests with malformed or suspicious URL parameters
• Log entries showing failed or unusual SAML processing events with external URLs
• Evidence of data exfiltration through the Ivanti appliance to attacker-controlled infrastructure

Detection Strategies

• Implement network monitoring for outbound connections from Ivanti appliances to unexpected internal destinations or metadata service endpoints
• Review and correlate SAML authentication logs for unusual request patterns or failed authentication attempts with external URLs
• Deploy web application firewall (WAF) rules to detect and block SSRF patterns in SAML requests
• Utilize threat intelligence feeds to identify known attacker infrastructure associated with Ivanti exploitation campaigns

Monitoring Recommendations

• Enable comprehensive logging on Ivanti appliances and forward logs to a centralized SIEM for analysis
• Monitor for connections to internal RFC 1918 addresses and cloud metadata services originating from the Ivanti appliance
• Implement behavioral analysis to detect anomalous authentication patterns on Ivanti devices
• Correlate Ivanti appliance activity with endpoint detection data to identify potential post-exploitation lateral movement

How to Mitigate CVE-2024-21893

Immediate Actions Required

• Apply the security patches provided by Ivanti immediately as this vulnerability is actively exploited in the wild
• Run the Ivanti Integrity Checker Tool (ICT) to verify appliance integrity and detect potential compromise
• If SAML authentication is not required, consider disabling the SAML component as a temporary mitigation
• Review network architecture to ensure Ivanti appliances have minimal access to internal resources and are properly segmented

Patch Information

Ivanti has released patches addressing CVE-2024-21893 for affected product versions. Organizations should consult the Ivanti Security Advisory for specific patch versions and upgrade instructions. Due to active exploitation tracked by CISA's Known Exploited Vulnerabilities catalog, organizations should prioritize patching and follow CISA's required remediation timelines if applicable.

Workarounds

• Import the mitigation.release.20240126.5.xml file provided by Ivanti as a temporary workaround if immediate patching is not possible
• Restrict access to the SAML authentication endpoints to trusted IP ranges using firewall rules
• Implement egress filtering to prevent the Ivanti appliance from making outbound connections to unauthorized destinations
• Consider temporarily taking affected appliances offline or routing traffic through alternate access methods until patches are applied

# Example egress filtering - block metadata service access from Ivanti appliance
iptables -A OUTPUT -d 169.254.169.254 -j DROP

# Block access to internal network ranges from Ivanti appliance (adjust for your network)
iptables -A OUTPUT -d 10.0.0.0/8 -j DROP
iptables -A OUTPUT -d 172.16.0.0/12 -j DROP
iptables -A OUTPUT -d 192.168.0.0/16 -j DROP