CVE-2018-1356 in FortiSandbox
Summary
by MITRE
A reflected Cross-Site-Scripting (XSS) vulnerability in Fortinet FortiSandbox before 3.0 may allow an attacker to execute unauthorized code or commands via the back_url parameter in the file scan component.
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Analysis
by VulDB Data Team • 08/28/2023
This vulnerability resides within Fortinet FortiSandbox version 3.0 and earlier, representing a critical reflected cross-site scripting flaw that directly impacts the system's security posture. The vulnerability specifically affects the file scan component where the back_url parameter is improperly handled, creating an avenue for malicious actors to inject and execute unauthorized code or commands. The reflected nature of this XSS vulnerability means that the malicious script is reflected off the web server and executed in the victim's browser, making it particularly dangerous as it can be delivered through various attack vectors including phishing emails, malicious links, or compromised websites.
The technical flaw stems from insufficient input validation and output encoding within the FortiSandbox application's file scan functionality. When the back_url parameter is processed without proper sanitization, it allows attackers to inject malicious JavaScript code that gets executed in the context of the victim's browser session. This vulnerability operates at the application layer and can be exploited through HTTP requests that contain crafted payloads in the back_url parameter, making it accessible via standard web browser interactions. The flaw essentially creates a persistent injection point where attacker-controlled content can be executed within the victim's browser environment, potentially leading to session hijacking, credential theft, or further exploitation of the compromised system.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a potential foothold for more sophisticated attacks within the network environment. Successful exploitation could enable attackers to manipulate the FortiSandbox's file scanning functionality, potentially allowing them to bypass security controls, access sensitive data, or redirect users to malicious websites. The vulnerability is particularly concerning in enterprise environments where FortiSandbox is used for security monitoring and threat analysis, as it could be leveraged to compromise the very security infrastructure designed to protect against threats. This creates a dangerous scenario where the security tool itself becomes a potential vector for attack, undermining the organization's overall security posture and potentially enabling lateral movement within the network.
Organizations should implement immediate mitigations including applying the vendor-provided patches and updates for FortiSandbox version 3.0 and later releases, which address the reflected XSS vulnerability through proper input validation and output encoding mechanisms. Network segmentation and web application firewalls should be configured to monitor and filter traffic containing suspicious back_url parameters, while security teams should conduct thorough penetration testing to identify any potential exploitation attempts. The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and it maps to ATT&CK technique T1059.007 for script-based attacks, highlighting the need for comprehensive defensive measures. Additionally, implementing strict input validation controls, regular security assessments, and employee training on recognizing phishing attempts will further reduce the risk of successful exploitation. Organizations should also consider implementing automated monitoring solutions that can detect anomalous patterns in the file scan component usage that might indicate exploitation attempts.