CVE-2016-5235 in WebSafe Alert Server
Summary
by MITRE
A Cross Site Scripting (XSS) vulnerability in versions of F5 WebSafe Dashboard 3.9.x and earlier, aka F5 WebSafe Alert Server, allows an unauthenticated user to inject HTML via a crafted alert.
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Analysis
by VulDB Data Team • 10/15/2023
The CVE-2016-5235 vulnerability represents a critical cross site scripting flaw within F5 WebSafe Dashboard versions 3.9.x and earlier, which also affects the F5 WebSafe Alert Server component. This vulnerability exposes the system to unauthorized code injection attacks that can be executed by any unauthenticated user without requiring prior access credentials or privileges. The flaw specifically manifests when the system processes alert messages that contain crafted HTML content, creating an opportunity for malicious actors to exploit the application's input validation mechanisms and execute arbitrary scripts within the context of a victim's browser session.
The technical nature of this vulnerability falls under CWE-79, which specifically addresses Cross-Site Scripting flaws in software applications. This classification indicates that the vulnerability stems from insufficient input sanitization and output encoding within the WebSafe Dashboard's alert processing functionality. The vulnerability allows attackers to inject malicious HTML content into alert notifications, which are then rendered by client browsers without proper sanitization. This creates a persistent threat vector where attackers can manipulate the dashboard interface to execute scripts that can steal session cookies, redirect users to malicious sites, or perform actions on behalf of authenticated users.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to establish persistent access to the dashboard environment and potentially escalate privileges within the system. An attacker could craft malicious alerts that, when viewed by administrators or other users, would execute malicious JavaScript code in their browser context. This could lead to session hijacking, data exfiltration, or the establishment of backdoor access points within the network monitoring infrastructure. The unauthenticated nature of the attack means that even users without legitimate access credentials can exploit this vulnerability, making it particularly dangerous for organizations that rely on the dashboard for security monitoring and alert management.
Mitigation strategies for CVE-2016-5235 should focus on immediate patching of affected F5 WebSafe Dashboard versions, implementing proper input validation and output encoding mechanisms, and deploying web application firewalls to filter malicious content. Organizations should also consider implementing content security policies to prevent script execution in alert contexts, and establish monitoring procedures to detect unusual alert patterns that may indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.007 for scripting and T1566.001 for credential harvesting, highlighting the potential for attackers to leverage this flaw for both initial access and lateral movement within the network infrastructure. Regular security assessments and vulnerability scanning should be conducted to ensure that all components of the F5 WebSafe suite remain protected against similar scripting vulnerabilities.