CVE-2024-31156 is a stored cross-site scripting (XSS) vulnerability classified under CWE-79 found in the F5 BIG-IP Configuration utility, specifically in an undisclosed page. This vulnerability allows an attacker to inject malicious JavaScript code that is stored and later executed in the context of the currently logged-in user’s browser session. The affected versions include 15.1.0, 16.1.0, and 17.1.0 of the BIG-IP software. Exploitation requires the attacker to have at least low privileges (PR:L) and user interaction (UI:R), such as tricking an authenticated user into visiting a crafted page or clicking a malicious link. The vulnerability is remotely exploitable over the network (AV:N) without complex attack conditions (AC:L). The impact is severe, affecting confidentiality, integrity, and availability (C:H/I:H/A:H) of the BIG-IP management interface, potentially allowing attackers to steal credentials, perform unauthorized actions, or disrupt network traffic management. Although no public exploits are reported yet, the vulnerability’s presence in a critical network device management platform makes it a high-risk issue. The vulnerability does not affect versions that have reached End of Technical Support (EoTS). The lack of a disclosed patch link suggests that remediation may require vendor updates or configuration changes once available. The vulnerability was published on May 8, 2024, indicating recent discovery and disclosure.

For European organizations, this vulnerability poses a significant risk due to the widespread use of F5 BIG-IP devices in enterprise and service provider networks for load balancing, application delivery, and security functions. Successful exploitation can lead to unauthorized access to the management interface, enabling attackers to manipulate network traffic, exfiltrate sensitive data, or disrupt critical services. This can impact confidentiality by exposing administrative credentials and session tokens, integrity by allowing unauthorized configuration changes, and availability by potentially disabling or degrading network services. Given the critical role of BIG-IP devices in infrastructure, exploitation could cascade into broader network compromise. European sectors such as finance, telecommunications, government, and critical infrastructure are particularly vulnerable due to their reliance on robust network management and security. The requirement for user interaction and some privilege reduces the attack surface but does not eliminate risk, especially in environments with multiple administrators or where phishing attacks are common. The absence of known exploits currently provides a window for proactive mitigation.

1. Immediately restrict access to the BIG-IP Configuration utility management interface to trusted IP addresses and networks using firewall rules or access control lists (ACLs). 2. Enforce multi-factor authentication (MFA) for all administrative users to reduce the risk of credential compromise. 3. Educate administrators to avoid clicking on suspicious links or opening untrusted content while logged into the BIG-IP management interface. 4. Monitor BIG-IP logs and network traffic for unusual activity indicative of attempted XSS exploitation or unauthorized access. 5. Apply vendor patches or updates as soon as they become available; coordinate with F5 support for timelines and interim workarounds. 6. Consider deploying web application firewalls (WAF) or reverse proxies that can detect and block XSS payloads targeting the management interface. 7. Regularly audit user privileges and remove unnecessary administrative accounts to minimize the number of potential targets. 8. Implement network segmentation to isolate management interfaces from general user networks, reducing exposure. 9. Use Content Security Policy (CSP) headers if configurable on the management interface to mitigate XSS impact. 10. Stay informed through F5 advisories and security bulletins for updates on this vulnerability.