CVE-2025-11718 is a vulnerability identified in Mozilla Firefox for Android versions prior to 144, where the browser's address bar is hidden during scrolling. The issue arises because a malicious webpage can exploit the visibilitychange event to create a fake address bar overlay that mimics the legitimate one. This spoofing technique can deceive users into trusting a fraudulent URL, facilitating phishing attacks or other forms of social engineering. The vulnerability is classified under CWE-451 (User Interface Misrepresentation), indicating that the user interface can be manipulated to mislead users. The CVSS v3.1 base score is 6.5 (medium), with an attack vector of network (remote), low attack complexity, no privileges required, but user interaction is necessary. The impact is primarily on integrity, as the attacker can misrepresent the URL, but confidentiality and availability remain unaffected. No known exploits have been reported in the wild, and no official patches have been released yet. The vulnerability specifically affects Firefox on Android, leveraging the browser's UI behavior during scroll events to execute the spoofing. This attack vector is subtle and can be difficult for users to detect, increasing its potential effectiveness in phishing campaigns.

For European organizations, this vulnerability poses a significant risk primarily in the realm of phishing and social engineering attacks targeting mobile users. Employees or customers using Firefox on Android devices could be tricked into entering sensitive information on fake websites that appear legitimate due to the spoofed address bar. This can lead to credential theft, unauthorized access, and potential downstream compromise of corporate resources. The integrity of user trust in web sessions is undermined, which can have reputational consequences for organizations if attackers impersonate their services. Since the vulnerability requires user interaction and is limited to Firefox on Android, the scope is somewhat constrained; however, given the widespread use of mobile devices and Firefox in Europe, the risk remains notable. The absence of patches at the time of disclosure increases the window of exposure. Organizations with mobile-first strategies, remote workforces, or customer portals accessed via mobile browsers are particularly vulnerable.

1. Educate users about the risk of phishing attacks that exploit UI spoofing, emphasizing caution when interacting with address bars or unexpected browser behavior on mobile devices. 2. Encourage users to verify URLs by manually typing them or using bookmarks rather than relying solely on the address bar display. 3. Implement mobile device management (MDM) policies to restrict installation of untrusted apps and enforce browser update policies. 4. Use browser security extensions or content blockers that can limit JavaScript execution on untrusted or unknown websites, reducing the attack surface. 5. Monitor Mozilla’s security advisories closely and prioritize patching Firefox on Android as soon as a fix becomes available. 6. For organizations providing web services, implement multi-factor authentication (MFA) to mitigate the impact of credential theft. 7. Consider deploying network-level protections such as DNS filtering and web proxies that can detect and block known phishing domains. 8. Conduct phishing simulation exercises tailored to mobile scenarios to raise awareness and test user response.