CVE-2024-27782: Fortinet FortiAIOps Auth Bypass Vulnerability

CVE-2024-27782 Overview

CVE-2024-27782 is a critical insufficient session expiration vulnerability (CWE-613) affecting Fortinet FortiAIOps version 2.0.0. This weakness allows attackers to re-use stolen old session tokens to perform unauthorized operations via crafted requests. The vulnerability stems from improper session management that fails to adequately invalidate or expire session tokens after logout or timeout events.

Critical Impact

Attackers can hijack valid user sessions using stolen or captured session tokens, enabling unauthorized access to FortiAIOps management functions, configuration changes, and sensitive network operations data.

Affected Products

• Fortinet FortiAIOps version 2.0.0

Discovery Timeline

• 2024-07-09 - CVE CVE-2024-27782 published to NVD
• 2026-01-09 - Last updated in NVD database

Technical Details for CVE-2024-27782

Vulnerability Analysis

This vulnerability involves multiple insufficient session expiration weaknesses in FortiAIOps. Session tokens that should be invalidated after user logout or inactivity periods remain valid indefinitely or for extended periods. An attacker who has obtained a session token through various means—such as network interception, cross-site scripting attacks, or accessing browser history—can leverage these tokens to impersonate legitimate users.

The vulnerability allows unauthenticated remote attackers to gain full access to FortiAIOps functionality without requiring any user interaction. Once an attacker obtains a valid session token, they can craft requests to the FortiAIOps API or web interface to perform any action the original user was authorized to execute.

Root Cause

The root cause of CVE-2024-27782 lies in improper implementation of session lifecycle management within FortiAIOps. Specifically, the application fails to properly invalidate session tokens when users log out, does not enforce appropriate session timeout mechanisms, and may not properly bind session tokens to other user-specific attributes (such as IP address or user agent) that would prevent token reuse from different contexts.

Attack Vector

The attack requires network access to the FortiAIOps application and possession of a valid session token. An attacker can obtain session tokens through several methods:

1. Network Interception: If sessions are transmitted over unencrypted or weakly encrypted channels, attackers can capture tokens via man-in-the-middle attacks
2. Cross-Site Scripting: XSS vulnerabilities in the application or related systems could allow token theft
3. Browser Cache/History Access: Physical or remote access to a user's browser could expose session tokens
4. Session Token Prediction: Weak session token generation algorithms could allow attackers to predict valid tokens

Once a token is obtained, the attacker crafts HTTP requests including the stolen session identifier to perform unauthorized operations against the FortiAIOps management interface.

Detection Methods for CVE-2024-27782

Indicators of Compromise

• Unusual session activity originating from IP addresses different from the legitimate user's known locations
• Multiple concurrent sessions for a single user account from geographically disparate locations
• Session tokens being used after a user has explicitly logged out
• API or web interface requests occurring outside normal business hours for specific user accounts

Detection Strategies

• Implement session anomaly detection to identify sessions being used from multiple IP addresses or user agents
• Monitor authentication logs for session tokens that appear after logout events have been recorded
• Deploy network monitoring to detect session token transmission patterns that may indicate interception attempts
• Correlate FortiAIOps access logs with user behavior baselines to identify deviations

Monitoring Recommendations

• Enable verbose logging on FortiAIOps to capture session creation, usage, and termination events
• Configure SIEM rules to alert on session reuse patterns consistent with token hijacking
• Implement real-time alerting for privileged operations performed by sessions exhibiting suspicious characteristics
• Review FortiAIOps audit logs regularly for signs of unauthorized configuration changes or data access

How to Mitigate CVE-2024-27782

Immediate Actions Required

• Upgrade FortiAIOps to a patched version as specified in the Fortinet security advisory
• Force logout of all active sessions and require re-authentication after applying patches
• Review access logs for any signs of unauthorized access using stolen session tokens
• Implement network segmentation to limit exposure of FortiAIOps management interface

Patch Information

Fortinet has released a security advisory addressing this vulnerability. Administrators should consult the Fortinet Security Advisory FG-IR-24-069 for specific patched versions and upgrade instructions. It is critical to apply the vendor-provided patches as soon as possible given the critical severity of this vulnerability.

Workarounds

• Restrict network access to FortiAIOps management interfaces using firewall rules and access control lists
• Implement additional authentication factors where possible to reduce the impact of session token compromise
• Configure shorter session timeout values if the application allows such customization
• Enable HTTPS-only access and ensure secure cookie attributes are properly configured

# Example network access restriction (firewall configuration)
# Restrict FortiAIOps management access to trusted administrator networks only
# Consult your specific firewall documentation for exact syntax

# Verify current FortiAIOps version
# Follow vendor upgrade procedures from FG-IR-24-069 advisory