CVE-2016-5236 in WebSafe Alert Server
Summary
by MITRE
Cross-Site-Scripting (XSS) vulnerabilities in F5 WebSafe Dashboard 3.9.5 and earlier, aka F5 WebSafe Alert Server, allow privileged authenticated users to inject arbitrary web script or HTML when creating a new user, account or signature.
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Analysis
by VulDB Data Team • 10/15/2023
The vulnerability identified as CVE-2016-5236 represents a critical cross-site scripting flaw within F5 WebSafe Dashboard version 3.9.5 and earlier releases, which operates under the broader F5 WebSafe Alert Server framework. This vulnerability specifically affects privileged authenticated users who possess the ability to create new user accounts, manage accounts, or establish security signatures within the system. The flaw stems from insufficient input validation and output encoding mechanisms that fail to properly sanitize user-supplied data before it is rendered in web interfaces, creating an environment where malicious scripts can be injected and subsequently executed in the context of other users' browsers.
The technical implementation of this vulnerability resides in the web application's handling of user creation and management functions where input fields for user attributes, account details, or signature definitions do not adequately filter or encode special characters that could be interpreted as executable script code. When privileged users create or modify these entities, the system fails to properly escape or validate the input data, allowing attackers to inject malicious payloads such as javascript code, html tags, or other script-based attacks that can be executed when legitimate users view the affected data. This represents a classic reflected cross-site scripting vulnerability where the malicious code is stored on the server and executed when other users access the compromised data.
The operational impact of this vulnerability extends beyond simple data corruption or unauthorized access, as it can enable attackers to escalate privileges, steal session cookies, perform actions on behalf of legitimate users, or redirect victims to malicious websites. The vulnerability's exploitation requires only authenticated access, making it particularly dangerous as it can be leveraged by insiders or compromised accounts to establish persistent access to the system. The affected environment typically includes organizations using F5 WebSafe Dashboard for security monitoring and alert management, where the compromised system could provide access to critical security information and potentially allow attackers to bypass security controls or manipulate security policies. This vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws and can be mapped to ATT&CK technique T1059.007 for script execution through web interfaces.
Mitigation strategies for CVE-2016-5236 should prioritize immediate patching of affected F5 WebSafe Dashboard installations to version 3.9.6 or later, which contains the necessary input validation and output encoding fixes. Organizations should implement additional defensive measures including strict input validation at multiple layers, comprehensive output encoding for all user-supplied data, regular security code reviews, and monitoring for suspicious user activities. Network segmentation and least privilege access controls can help limit the potential impact if the vulnerability is exploited, while security awareness training for administrators can reduce the risk of insider threats. The vulnerability also underscores the importance of maintaining up-to-date security patches and implementing robust security monitoring to detect unauthorized access attempts or unusual user behavior patterns that might indicate exploitation attempts.