CVE-2018-15313 in BIG-IP AFM
Summary
by MITRE
On F5 BIG-IP AFM 13.0.0-13.1.1.1 and 12.1.0-12.1.3.6, there is a Reflected Cross Site Scripting vulnerability in undisclosed TMUI page.
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Analysis
by VulDB Data Team • 05/30/2023
The vulnerability CVE-2018-15313 represents a critical reflected cross site scripting flaw within the F5 BIG-IP Advanced Firewall Manager component. This security weakness affects specific versions of the F5 BIG-IP system including releases 13.0.0 through 13.1.1.1 and 12.1.0 through 12.1.3.6. The vulnerability manifests in an undisclosed TMUI page, which serves as the management interface for the BIG-IP system. The TMUI (Traffic Management User Interface) provides administrative access to configure and manage network security policies, making this flaw particularly concerning from a cybersecurity perspective. The reflected XSS vulnerability occurs when the application fails to properly sanitize user input before reflecting it back to the user's browser, creating an opportunity for attackers to inject malicious scripts.
The technical implementation of this vulnerability involves the TMUI component failing to validate or escape user-supplied data that is subsequently reflected in HTTP responses. When an attacker crafts a malicious payload and delivers it to a victim through social engineering or other means, the vulnerable application reflects this script back to the user's browser, where it executes in the context of the victim's session. This behavior aligns with CWE-79 which specifically addresses cross-site scripting vulnerabilities where untrusted data is reflected back to users without proper sanitization. The attack vector typically involves manipulating URL parameters or form fields that are processed by the TMUI interface, allowing malicious JavaScript code to be executed in the victim's browser session.
The operational impact of this vulnerability extends beyond simple script execution as it enables attackers to perform session hijacking, steal administrative credentials, and potentially gain full control over the affected BIG-IP system. Since the BIG-IP AFM component manages critical network security policies and firewall rules, successful exploitation could allow attackers to bypass security controls, modify access policies, or redirect traffic flows. The vulnerability creates a persistent threat vector that could be exploited by attackers with minimal technical skill, as reflected XSS attacks often require only crafting a malicious URL and tricking users into clicking it. This makes the vulnerability particularly dangerous in enterprise environments where administrators frequently interact with web-based management interfaces.
Mitigation strategies for CVE-2018-15313 should prioritize immediate patching of affected systems to address the reflected XSS vulnerability in the TMUI interface. Organizations must ensure that all affected F5 BIG-IP systems are updated to versions that contain the necessary security fixes. Network segmentation and access controls should be implemented to limit exposure of the TMUI interface to trusted networks only, reducing the attack surface available to potential adversaries. Additional protective measures include implementing web application firewalls to detect and block malicious payloads targeting the TMUI interface, enabling strict content security policies to prevent script execution, and conducting regular security assessments to identify similar vulnerabilities in other components of the BIG-IP system. The vulnerability demonstrates the importance of proper input validation and output encoding practices as outlined in the OWASP Top Ten and aligns with ATT&CK technique T1059.007 which covers scripting through webshell execution, highlighting how such vulnerabilities can enable more sophisticated attack chains.