CVE-2020-9288 in FortiWLC
Summary
by MITRE
An improper neutralization of input vulnerability in FortiWLC 8.5.1 allows a remote authenticated attacker to perform a stored cross site scripting attack (XSS) via the ESS profile or the Radius Profile.
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Analysis
by VulDB Data Team • 10/26/2020
The vulnerability identified as CVE-2020-9288 represents a critical security flaw in FortiWLC 8.5.1 software that exposes organizations to persistent cross site scripting attacks. This issue stems from inadequate input validation mechanisms within the web-based management interface of the FortiWLC wireless controller, specifically affecting the ESS profile and RADIUS profile configuration sections. The vulnerability classification aligns with CWE-79 which describes improper neutralization of input during web page generation, making it a prime candidate for stored XSS exploitation techniques. Attackers leveraging this weakness can inject malicious scripts into profile configurations that persistently affect users who view these profiles, creating a dangerous attack surface for unauthorized access and data exfiltration.
The technical implementation of this vulnerability occurs when authenticated users with sufficient privileges interact with the ESS profile or RADIUS profile configuration interfaces. The system fails to properly sanitize user-supplied input before storing and rendering it within web pages, allowing attackers to inject malicious JavaScript code through profile parameters. This stored nature of the vulnerability means that once malicious input is submitted and saved, the injected scripts execute automatically whenever other users view the affected profiles. The attack requires only authentication privileges to the FortiWLC management interface, making it particularly dangerous as it can be exploited by insiders or compromised accounts with appropriate access rights.
The operational impact of CVE-2020-9288 extends beyond simple script execution, potentially enabling sophisticated attack chains that can compromise entire wireless network infrastructures. An attacker could leverage this vulnerability to steal session cookies, redirect users to malicious sites, perform unauthorized configuration changes, or even establish persistent backdoors within the wireless network management system. The stored XSS nature creates a long-term threat vector that remains active until the vulnerable profiles are manually reviewed and cleaned, or until the software is patched. Organizations using FortiWLC 8.5.1 are particularly vulnerable as the attack can persist across multiple user sessions and system restarts, making detection and remediation challenging. The vulnerability also creates potential for privilege escalation if attackers can manipulate administrative profiles or gain access to sensitive wireless network configurations.
Mitigation strategies for CVE-2020-9288 should focus on immediate software patching from Fortinet to address the input validation deficiencies in the web interface. Organizations should implement network segmentation and access controls to limit who can modify ESS and RADIUS profiles within the FortiWLC system. Regular monitoring of profile configurations and implementing web application firewalls can help detect and prevent malicious input injection attempts. Security teams should also conduct comprehensive audits of all wireless network configurations to identify and remediate any existing malicious payloads that may have been injected through this vulnerability. Additionally, implementing strict input validation policies and regular security assessments of web-based management interfaces can help prevent similar vulnerabilities from emerging in other network infrastructure components, aligning with industry best practices outlined in the NIST Cybersecurity Framework and MITRE ATT&CK framework for network security controls.