CVE-2017-7339 in FortiPortal
Summary
by MITRE
A Cross-Site Scripting vulnerability in Fortinet FortiPortal versions 4.0.0 and below allows an attacker to execute unauthorized code or commands via the 'Name' and 'Description' inputs in the 'Add Revision Backup' functionality.
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Analysis
by VulDB Data Team • 10/03/2020
The vulnerability identified as CVE-2017-7339 represents a critical cross-site scripting flaw within Fortinet FortiPortal authentication and access management systems. This issue affects versions 4.0.0 and earlier, exposing organizations to potential unauthorized code execution and command injection attacks through web interface manipulation. The vulnerability specifically targets the 'Add Revision Backup' functionality, which serves as a legitimate administrative feature for managing system configurations and backups.
The technical implementation of this flaw stems from inadequate input validation and output encoding within the web application's user interface components. When administrators or authorized users interact with the 'Name' and 'Description' fields during the revision backup process, the application fails to properly sanitize or escape user-supplied data before rendering it back to the browser. This creates an environment where malicious actors can inject malicious javascript code, html tags, or other script payloads that execute in the context of other users' browsers. The vulnerability falls under CWE-79 which specifically addresses Cross-Site Scripting flaws in web applications, where improper validation of user-controllable data leads to script execution in victim browsers.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to escalate privileges and gain unauthorized access to sensitive administrative functions. An attacker who successfully exploits this vulnerability can potentially impersonate legitimate users, access restricted system features, modify configuration parameters, or even extract sensitive information from the system. The attack vector is particularly concerning because it leverages legitimate administrative functionality, making detection more difficult and the attack appear more trustworthy to system administrators. This vulnerability aligns with ATT&CK technique T1059.007 which describes the use of script-based payloads in web applications, and T1566 which covers social engineering techniques that exploit web application vulnerabilities.
Organizations using affected FortiPortal versions should immediately implement multiple layers of mitigation strategies to address this vulnerability. The primary recommendation involves upgrading to Fortinet FortiPortal versions 4.0.1 or later, which contain the necessary patches to properly sanitize user inputs and prevent script injection attacks. Additionally, implementing proper input validation and output encoding measures at the application level can provide defense-in-depth protection. Network segmentation and monitoring of administrative interfaces can help detect suspicious activities related to backup and configuration management functions. Security teams should also conduct comprehensive penetration testing to identify any potential exploitation attempts and establish baseline configurations that minimize the attack surface. The vulnerability demonstrates the critical importance of proper input sanitization in web applications and serves as a reminder of the potential consequences when user-controllable data is not properly validated before being rendered in browser contexts.