CVE-2025-24470: Fortinet FortiPortal Path Traversal Flaw

CVE-2025-24470 Overview

An Improper Resolution of Path Equivalence vulnerability (CWE-41) has been identified in Fortinet FortiPortal, a customer-facing portal solution used for managing FortiGate devices. This vulnerability allows remote unauthenticated attackers to retrieve source code from affected FortiPortal installations through specially crafted HTTP requests, potentially exposing sensitive application logic and credentials.

Critical Impact

Remote unauthenticated attackers can exploit this path equivalence flaw to access and download source code files, potentially revealing hardcoded credentials, API keys, business logic, and other sensitive implementation details that could facilitate further attacks.

Affected Products

• FortiPortal 7.4.0 through 7.4.2
• FortiPortal 7.2.0 through 7.2.6
• FortiPortal 7.0.0 through 7.0.11

Discovery Timeline

• 2025-02-11 - CVE-2025-24470 published to NVD
• 2025-07-22 - Last updated in NVD database

Technical Details for CVE-2025-24470

Vulnerability Analysis

This vulnerability stems from improper handling of path equivalence in FortiPortal's web server component. Path equivalence vulnerabilities occur when a system fails to properly normalize or validate file path requests, allowing attackers to access files outside intended directories or bypass access controls by using alternate path representations.

In this case, FortiPortal does not adequately resolve equivalent path representations in HTTP requests, enabling attackers to craft malicious requests that bypass security controls designed to protect source code and other sensitive files. The network-based attack vector with no authentication required significantly increases the exploitability of this flaw, as any attacker with network access to a FortiPortal instance can attempt exploitation.

The scope of this vulnerability is particularly concerning as successful exploitation results in confidentiality impact to resources beyond the vulnerable component. Source code disclosure can reveal application architecture, authentication mechanisms, database connection strings, and internal API endpoints that attackers can leverage for subsequent attacks.

Root Cause

The root cause of CVE-2025-24470 is improper path normalization within FortiPortal's request handling logic. When processing HTTP requests for static or dynamic resources, the application fails to properly resolve path equivalences such as URL-encoded characters, double encoding, or alternative path separators. This allows attackers to construct requests that appear valid to initial security checks but resolve to protected file locations when processed by the file system.

The CWE-41 (Improper Resolution of Path Equivalence) classification indicates that the vulnerability arises from inconsistent interpretation of file paths between different components of the application stack.

Attack Vector

Attackers can exploit this vulnerability by sending crafted HTTP requests to a vulnerable FortiPortal instance. The attack requires no authentication and can be performed remotely over the network. By manipulating path components within HTTP requests, attackers can bypass access controls and retrieve source code files that should not be publicly accessible.

The attack flow typically involves:

1. Identifying a FortiPortal instance exposed to the network
2. Crafting HTTP requests with manipulated path components
3. Receiving source code or configuration files in the HTTP response
4. Analyzing disclosed files for credentials, API keys, or exploitable logic

Specific exploitation techniques are documented in the Fortinet Security Advisory FG-IR-25-015. Organizations should review this advisory for detailed technical information and indicators of compromise.

Detection Methods for CVE-2025-24470

Indicators of Compromise

• Unusual HTTP requests containing encoded path characters or path traversal sequences targeting FortiPortal
• Access logs showing requests for source code file extensions (.php, .py, .jsp) from external IP addresses
• Multiple requests from the same source attempting various path manipulation techniques
• Unexpected outbound data transfers containing application source code signatures

Detection Strategies

• Monitor FortiPortal access logs for HTTP requests containing URL-encoded characters, double encoding, or unusual path patterns
• Implement web application firewall (WAF) rules to detect and block path traversal and path equivalence attack patterns
• Deploy network intrusion detection signatures for CWE-41 exploitation attempts targeting FortiPortal endpoints
• Conduct regular log analysis to identify reconnaissance activity against FortiPortal installations

Monitoring Recommendations

• Enable verbose logging on FortiPortal instances to capture full request URIs and response codes
• Configure SIEM alerts for anomalous access patterns to FortiPortal administration endpoints
• Implement file integrity monitoring on FortiPortal source code directories to detect unauthorized access attempts
• Review authentication logs for any suspicious activity following potential source code disclosure

How to Mitigate CVE-2025-24470

Immediate Actions Required

• Upgrade FortiPortal to a patched version immediately: 7.4.3 or later for 7.4.x branch, 7.2.7 or later for 7.2.x branch, or 7.0.12 or later for 7.0.x branch
• Restrict network access to FortiPortal instances using firewall rules to limit exposure
• Implement web application firewall rules to filter malicious path manipulation requests
• Audit access logs for evidence of exploitation attempts and investigate any suspicious activity

Patch Information

Fortinet has released security patches addressing this vulnerability. Organizations should apply updates according to their deployed version branch:

• FortiPortal 7.4.x: Upgrade to version 7.4.3 or later
• FortiPortal 7.2.x: Upgrade to version 7.2.7 or later
• FortiPortal 7.0.x: Upgrade to version 7.0.12 or later

Refer to the Fortinet Security Advisory FG-IR-25-015 for complete patch details and upgrade instructions.

Workarounds

• Deploy a reverse proxy or web application firewall in front of FortiPortal to filter malicious requests
• Implement network segmentation to limit access to FortiPortal from trusted networks only
• Enable additional access controls at the network level to restrict which IP addresses can reach FortiPortal
• Consider temporarily disabling public-facing FortiPortal access until patches can be applied

# Example: Restrict FortiPortal access to trusted networks using iptables
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 192.168.0.0/16 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP