CVE-2024-3378 Overview
CVE-2024-3378 is a reflected cross-site scripting (XSS) vulnerability in the iboss Secure Web Gateway versions up to 10.1. The flaw resides in the /login endpoint of the Login Portal component. Attackers can manipulate the redirectUrl parameter to inject arbitrary script content that executes in the victim's browser session. The issue is remotely exploitable and requires user interaction, typically by clicking a crafted link. Public disclosure of the exploit has occurred, and iboss addressed the issue in version 10.2.0.160.
Critical Impact
Successful exploitation enables session hijacking, credential theft through crafted login pages, and delivery of malicious payloads to administrators authenticating to the gateway.
Affected Products
- iboss Secure Web Gateway versions up to and including 10.1
- Login Portal component (/login endpoint)
- Fixed in iboss Secure Web Gateway version 10.2.0.160
Discovery Timeline
- 2024-04-06 - CVE-2024-3378 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-3378
Vulnerability Analysis
The vulnerability is a reflected cross-site scripting flaw [CWE-79] in the Login Portal of iboss Secure Web Gateway. The /login endpoint accepts a redirectUrl query parameter without proper output encoding or input sanitization. An attacker crafts a URL containing JavaScript payloads in the redirectUrl parameter and delivers it to a victim. When the victim loads the URL, the injected script executes in the context of the gateway's login domain.
The scope-change indicator in the CVSS vector reflects that script execution affects resources beyond the vulnerable component, such as authenticated administrator sessions or cached credentials. Because Secure Web Gateways typically serve as authentication and policy enforcement points, exploitation offers attackers a valuable pivot into administrative workflows.
Root Cause
The root cause is missing input validation and output encoding on the redirectUrl parameter before it is reflected back into the HTTP response. User-controlled data flows directly into the response body or a client-side redirect handler without contextual escaping. This allows attacker-supplied HTML and JavaScript to be interpreted by the browser.
Attack Vector
Exploitation requires an attacker to craft a malicious URL targeting the vulnerable /login endpoint with a JavaScript payload embedded in the redirectUrl parameter. The attacker then delivers the URL through phishing emails, chat messages, or malicious web content. When an administrator or user clicks the link and authenticates, the injected script executes with access to session cookies, form data, and DOM content of the login portal.
No authentication is required to construct the payload URL. The attack chain typically targets privileged administrators to escalate impact toward gateway configuration changes or credential harvesting.
No verified public exploit code is available for reproduction. See the GitHub CVE-2024-3378 write-up and VulDB entry #259501 for additional technical details.
Detection Methods for CVE-2024-3378
Indicators of Compromise
- HTTP requests to /login containing redirectUrl parameter values with URL-encoded <script>, javascript:, onerror=, or onload= substrings
- Referer headers pointing to external, untrusted domains when accessing the iboss login portal
- Unusual outbound requests from administrator browsers immediately after authenticating to the gateway
- Log entries showing redirectUrl values that decode to non-relative URLs or contain HTML entities
Detection Strategies
- Deploy web application firewall rules that inspect the redirectUrl query parameter for script-injection patterns and reject non-allowlisted redirect targets
- Correlate proxy and gateway access logs for repeated /login requests carrying suspicious redirectUrl values from a single source
- Monitor browser console errors and Content Security Policy violation reports from administrator workstations
Monitoring Recommendations
- Ingest iboss gateway access logs into a centralized SIEM and alert on query strings containing script tags, event handlers, or protocol handlers such as javascript: or data:
- Baseline normal redirectUrl values and flag deviations that include external hosts or encoded HTML
- Track administrator authentication events immediately preceded by clicks on externally referred links
How to Mitigate CVE-2024-3378
Immediate Actions Required
- Upgrade iboss Secure Web Gateway to version 10.2.0.160 or later on all appliances
- Inventory all instances of iboss Secure Web Gateway to confirm patch coverage across managed and remote sites
- Communicate phishing risk to administrators and instruct them to avoid clicking gateway login links from untrusted sources
Patch Information
Upgrade to iboss Secure Web Gateway 10.2.0.160 or later, which addresses the redirectUrl parameter handling in the /login endpoint. No vendor advisory URL is listed in the NVD entry. Refer to iboss support channels for release notes and upgrade guidance.
Workarounds
- Restrict access to the administrative login portal to trusted management networks using firewall or ACL controls
- Implement a strict Content Security Policy on the login portal to block inline script execution
- Enforce allowlisting of permitted redirect destinations at a reverse proxy in front of the gateway until patching is complete
- Require administrators to authenticate from managed workstations with browser isolation or URL filtering enabled
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.