CVE-2024-35280 Overview
CVE-2024-35280 is a reflected cross-site scripting (XSS) vulnerability [CWE-79] affecting the recovery endpoints of Fortinet FortiDeceptor. The flaw stems from improper neutralization of user-supplied input during web page generation. An unauthenticated attacker can craft a malicious URL that, when visited by a target user, executes attacker-controlled script in the victim's browser session.
Critical Impact
Successful exploitation allows an attacker to execute script in the context of the FortiDeceptor web interface, potentially stealing session tokens, redirecting administrators, or performing actions on their behalf.
Affected Products
- Fortinet FortiDeceptor 5.3.0 and 5.2.0
- Fortinet FortiDeceptor 5.1, 5.0, 4.3, 4.2, 4.1, 4.0 (all versions)
- Fortinet FortiDeceptor 3.3, 3.2, 3.1, 3.0 (all versions)
Discovery Timeline
- 2025-01-15 - CVE-2024-35280 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-35280
Vulnerability Analysis
The vulnerability resides in the recovery endpoints of the FortiDeceptor management interface. These endpoints reflect request parameters into the HTTP response without applying proper output encoding or contextual sanitization. As a result, script content supplied by an attacker is rendered by the victim's browser as part of the returned page.
Reflected XSS in an administrative appliance interface is particularly relevant because FortiDeceptor is a deception platform used by security teams. Compromise of an administrator session can expose deception topology, decoy configurations, and lure telemetry that adversaries would otherwise never observe.
Exploitation requires the target to click a crafted link or interact with attacker-controlled content. The scope change indicated in the CVSS vector reflects that injected script executes in the browser's security context rather than the vulnerable server itself.
Root Cause
The root cause is missing or insufficient output encoding when recovery endpoint parameters are echoed back into HTML responses. Standard defenses such as context-aware HTML entity encoding and a restrictive Content Security Policy are not enforced for these routes.
Attack Vector
An attacker crafts a URL targeting an affected FortiDeceptor recovery endpoint with a payload embedded in a reflected parameter. The attacker delivers the URL to an authenticated administrator through phishing, chat, or a watering-hole page. When the administrator opens the link, script executes inside the FortiDeceptor web session.
The vulnerability requires no privileges but does require user interaction. Refer to the Fortinet Security Advisory FG-IR-24-010 for vendor technical details. No public proof-of-concept or in-the-wild exploitation has been reported.
Detection Methods for CVE-2024-35280
Indicators of Compromise
- Web access logs on FortiDeceptor showing requests to recovery endpoints containing HTML tags, javascript: URIs, or encoded payload markers such as %3Cscript%3E.
- Administrator browser sessions issuing unexpected outbound requests to unfamiliar domains shortly after clicking an emailed link.
- Duplicate or anomalous administrator session tokens observed from geographically distinct IP addresses.
Detection Strategies
- Deploy web application firewall rules that flag reflected script patterns in query strings and POST bodies destined for the FortiDeceptor management interface.
- Correlate email or chat delivery of URLs referencing FortiDeceptor hostnames with subsequent administrator clicks.
- Inspect referrer headers on FortiDeceptor logins for external origins that indicate cross-site delivery.
Monitoring Recommendations
- Forward FortiDeceptor web server logs to a centralized SIEM and alert on recovery endpoint requests with suspicious character sets.
- Monitor administrator account activity for configuration changes performed immediately after suspicious link interaction.
- Track browser telemetry from privileged workstations for script-driven navigation to the appliance interface.
How to Mitigate CVE-2024-35280
Immediate Actions Required
- Upgrade FortiDeceptor to a fixed release as identified in the Fortinet Security Advisory FG-IR-24-010.
- Restrict access to the FortiDeceptor management interface to trusted management networks and jump hosts.
- Instruct administrators to avoid clicking untrusted links while authenticated to the appliance.
Patch Information
Fortinet has published fixed versions in advisory FG-IR-24-010. Administrators should consult the advisory to identify the appropriate upgrade path for their deployed branch, as versions 3.0 through 5.3.0 are affected. Apply vendor patches during the next available maintenance window.
Workarounds
- Enforce network-level access controls that limit which client IPs can reach the FortiDeceptor administrative interface.
- Require administrators to use a dedicated browser profile or privileged access workstation when managing the appliance.
- Deploy a reverse proxy or WAF in front of the management interface to block reflected XSS payload patterns until patches are applied.
# Example: restrict FortiDeceptor management access via upstream firewall
# Replace <mgmt_subnet> and <fortideceptor_ip> with your values
iptables -A FORWARD -s <mgmt_subnet> -d <fortideceptor_ip> -p tcp --dport 443 -j ACCEPT
iptables -A FORWARD -d <fortideceptor_ip> -p tcp --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
