CVE-2016-3196 in FortiAnalyzer
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Fortinet FortiAnalyzer 5.x before 5.2.6 and FortiManager 5.x before 5.2.6 allows remote authenticated users to inject arbitrary web script or HTML via the filename of an image uploaded in the report section.
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Analysis
by VulDB Data Team • 05/17/2018
The CVE-2016-3196 vulnerability represents a critical cross-site scripting flaw affecting Fortinet FortiAnalyzer and FortiManager products across version 5.x prior to 5.2.6. This vulnerability resides within the report section functionality where users can upload images, creating a pathway for malicious actors to execute arbitrary web scripts or HTML code. The issue stems from insufficient input validation and output encoding mechanisms within the image filename handling process, allowing attackers to inject malicious content that persists within the application's report generation system.
The technical exploitation of this vulnerability requires an attacker to possess valid authentication credentials, making it an authenticated XSS vulnerability rather than a purely remote threat. Attackers can leverage this weakness by uploading an image file with a malicious filename containing embedded script tags or other HTML content that gets rendered in subsequent report views. This creates a persistent XSS vector where the malicious code executes in the context of other users' browsers who view the compromised reports, potentially leading to session hijacking, credential theft, or redirection to malicious sites. The vulnerability aligns with CWE-79 which categorizes cross-site scripting as a code injection flaw occurring when untrusted data is directly incorporated into web pages without proper validation or encoding.
The operational impact of CVE-2016-3196 extends beyond simple script execution, as it can enable attackers to establish persistent access within network monitoring environments where FortiAnalyzer and FortiManager systems are deployed. These devices typically serve as central repositories for security logs and network monitoring data, making them attractive targets for attackers seeking to maintain long-term access or escalate privileges. The vulnerability can be exploited through the web interface of these security appliances, potentially allowing attackers to view sensitive security information, modify reports, or redirect users to phishing sites that appear legitimate within the trusted network environment.
Organizations using affected Fortinet products should prioritize immediate patching to address this vulnerability, as the security implications extend beyond simple XSS attacks. The vulnerability can be mitigated through proper input validation of file names during image uploads, implementing strict output encoding for all user-supplied content, and enforcing proper access controls within the report generation system. Network security teams should also consider implementing web application firewalls to detect and prevent malicious file upload attempts, while monitoring for anomalous behavior in report generation activities that might indicate exploitation attempts. This vulnerability demonstrates the importance of validating all user inputs and properly encoding output in security-critical applications, aligning with ATT&CK technique T1566 which covers credential access through various injection methods including XSS attacks.