CVE-2025-55028 is a medium-severity vulnerability affecting Mozilla Firefox for iOS versions prior to 142. The issue arises from the handling of JavaScript alert dialogs within the browser. Specifically, malicious web pages can execute repetitive JavaScript alert() calls, which can effectively lock the user interface (UI) by continuously displaying alert dialogs. This behavior impedes user interaction, as the user must dismiss each alert before proceeding, potentially leading to a denial of service (DoS) condition where the browser becomes unresponsive or unusable until the alerts are cleared. The vulnerability is categorized under CWE-400, which relates to uncontrolled resource consumption, indicating that the repeated alerts can exhaust UI resources or user patience, resulting in service disruption. The CVSS v3.1 score of 6.5 reflects a medium severity, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), but requiring user interaction (UI:R). The impact is limited to availability (A:H), with no confidentiality or integrity impact. No known exploits are currently reported in the wild, and no patches are linked yet, suggesting that mitigation may rely on updates from Mozilla once available. This vulnerability is specific to Firefox on iOS, leveraging the browser's JavaScript engine and alert dialog handling mechanisms to cause UI lockup and denial of service.

For European organizations, the primary impact of CVE-2025-55028 is the potential disruption of user productivity and service availability when using Firefox for iOS. Organizations with employees or clients relying on Firefox on iOS devices may experience temporary denial of service conditions when accessing malicious or compromised websites that exploit this vulnerability. This could affect web-based internal tools, customer portals, or any web applications accessed via Firefox on iOS, leading to operational delays or user frustration. While the vulnerability does not compromise data confidentiality or integrity, the availability impact can hinder business continuity, especially in sectors where mobile device usage is critical, such as finance, healthcare, and public services. Additionally, targeted exploitation could be used as part of a broader attack to distract or disrupt users during social engineering or phishing campaigns. However, the lack of known exploits and the requirement for user interaction reduce the immediacy of the threat. Still, organizations should be aware of this vulnerability as part of their mobile device security posture.

To mitigate CVE-2025-55028 effectively, European organizations should: 1) Ensure that all Firefox for iOS installations are updated promptly to version 142 or later once Mozilla releases the patch addressing this vulnerability. 2) Implement mobile device management (MDM) policies to enforce timely updates and restrict installation of outdated or vulnerable app versions. 3) Educate users about the risks of interacting with suspicious websites, emphasizing caution when unexpected alert dialogs appear repeatedly. 4) Employ web filtering solutions that can block access to known malicious URLs or domains that may exploit this vulnerability. 5) Monitor network traffic for unusual patterns indicative of repeated alert dialogs or DoS attempts originating from web browsing activities. 6) Consider alternative browsers on iOS for critical users until the vulnerability is patched, if feasible. These steps go beyond generic advice by focusing on update management, user awareness, and network-level controls tailored to the specific nature of this vulnerability.