CVE-2024-33505: Fortinet FortiAnalyzer Buffer Overflow Flaw

CVE-2024-33505 Overview

CVE-2024-33505 is a heap-based buffer overflow affecting Fortinet FortiAnalyzer, FortiManager, and FortiManager Cloud. The vulnerability resides in the HTTP request handling logic of the management interface. An unauthenticated remote attacker can send specially crafted HTTP requests to corrupt heap memory and escalate privileges on affected appliances.

The flaw is tracked under [CWE-122] (Heap-Based Buffer Overflow) and [CWE-787] (Out-of-Bounds Write). Fortinet documented the issue in advisory FG-IR-24-125.

Critical Impact
Successful exploitation allows attackers to escalate privileges on FortiAnalyzer and FortiManager appliances through network-accessible HTTP endpoints without prior authentication.

Affected Products

Fortinet FortiAnalyzer versions 7.4.0 through 7.4.2, 7.2.0 through 7.2.5, 7.0.0 through 7.0.12, and 6.4.0 through 6.4.14
Fortinet FortiManager versions 7.4.0 through 7.4.2, 7.2.0 through 7.2.5, 7.0.0 through 7.0.12, and 6.4.0 through 6.4.14
Fortinet FortiManager Cloud (affected releases per vendor advisory)

Discovery Timeline

2024-11-12 - CVE-2024-33505 published to the National Vulnerability Database (NVD)
2025-01-31 - Last updated in NVD database

Technical Details for CVE-2024-33505

Vulnerability Analysis

The vulnerability is a heap-based buffer overflow in the HTTP request processing path of FortiAnalyzer and FortiManager. The affected services accept HTTP input that is copied into a heap-allocated buffer without sufficient size validation. An attacker controls the length and content of the data written beyond the allocated bounds.

Writing past the allocated buffer corrupts adjacent heap metadata and application objects. Attackers can leverage this corruption to alter program control flow or modify in-memory privilege state. The result is an escalation of privilege within the management plane of the appliance.

FortiAnalyzer and FortiManager are centralized management and analytics platforms. Compromise of these systems gives attackers oversight of every downstream FortiGate and security device managed by the appliance. This makes the flaw a high-value pivot for lateral movement across Fortinet-managed environments.

Root Cause

The root cause is improper bounds checking when handling attacker-supplied data in HTTP request fields. The processing routine allocates a heap buffer and then writes input data without verifying that the input length fits the destination. This combination of [CWE-122] and [CWE-787] enables deterministic heap corruption from a single crafted request.

Attack Vector

The attack vector is network-based and requires no user interaction. An attacker sends crafted HTTP requests to the exposed management interface. Internet-exposed FortiAnalyzer or FortiManager instances are at direct risk, while internally exposed systems remain reachable from any host with network access to the management VLAN.

The vulnerability is exploited through HTTP requests with malformed length or structure fields that trigger the unsafe heap write. No verified public proof-of-concept code is currently published. See the Fortinet Security Advisory FG-IR-24-125 for vendor technical details.

Detection Methods for CVE-2024-33505

Indicators of Compromise

Unexpected httpsd or web management daemon crashes, restarts, or core dumps on FortiAnalyzer or FortiManager hosts
HTTP requests to the management interface containing oversized headers, malformed length fields, or anomalous binary payloads
New or unexpected administrative accounts and privilege changes within FortiAnalyzer or FortiManager configuration logs
Outbound connections from the appliance management interface to untrusted external addresses

Detection Strategies

Inspect web management logs for HTTP requests with abnormal sizes or non-standard URI patterns targeting management endpoints
Correlate appliance service restarts with preceding inbound HTTP traffic from non-administrative source addresses
Alert on configuration changes, account creation events, and privilege modifications that do not align with change-management records
Compare running firmware versions against the fixed releases listed in advisory FG-IR-24-125 to surface vulnerable assets

Monitoring Recommendations

Forward FortiAnalyzer and FortiManager system, event, and HTTP logs to a centralized SIEM for retention and correlation
Monitor network flows to TCP 443 and other management ports on these appliances from unexpected source ranges
Track administrative API usage patterns and flag deviations in request rate, source geography, or user agent
Review authentication and authorization audit trails on a recurring schedule for anomalous escalation events

How to Mitigate CVE-2024-33505

Immediate Actions Required

Upgrade FortiAnalyzer and FortiManager to fixed releases identified in Fortinet advisory FG-IR-24-125
Restrict management interface access to dedicated administrative networks and trusted jump hosts
Audit administrator accounts and recent configuration changes on affected appliances for unauthorized activity
Rotate credentials and API keys used by or stored on the affected FortiAnalyzer and FortiManager instances

Patch Information

Fortinet provides fixed builds for each affected branch of FortiAnalyzer, FortiManager, and FortiManager Cloud. Refer to advisory FG-IR-24-125 for the specific minimum patched versions per release train. Apply the upgrade following Fortinet's documented procedure and validate appliance health after reboot.

Workarounds

Limit inbound access to the management HTTP/HTTPS interface using trusted hosts configuration so only known administrative IP ranges can connect
Place FortiAnalyzer and FortiManager behind a dedicated management firewall and disallow internet exposure of the GUI
Disable unused administrative services and interfaces to reduce the reachable HTTP attack surface until patching is complete

bash

# Configuration example: restrict admin access using trusted hosts
config system admin
    edit "admin"
        set trusthost1 10.10.0.0 255.255.255.0
        set trusthost2 192.168.50.10 255.255.255.255
    next
end