CVE-2025-14021 is a vulnerability identified in the LINE client for iOS, specifically affecting versions prior to 14.14. The flaw resides in the in-app browser component, which is used to display web content within the app. The vulnerability allows attackers to perform address bar spoofing by executing malicious JavaScript code inside iframes. This JavaScript execution enables attackers to overlay malicious content while the address bar continues to display a legitimate, trusted URL, thereby deceiving users into believing they are interacting with a safe website. The attack vector requires no privileges or authentication but does require user interaction, such as clicking a malicious link within the app. The vulnerability's impact is primarily on the integrity of the displayed content and user trust, facilitating phishing attacks that could lead to credential theft or other social engineering outcomes. The CVSS score of 4.3 reflects a medium severity, indicating that while the attack is feasible and impactful, it does not directly compromise confidentiality or availability. No known exploits are reported in the wild as of the publication date. The vulnerability highlights the risks inherent in embedded browsers within mobile applications, especially those widely used for communication like LINE. The absence of a patch link suggests that users should update to version 14.14 or later once available to remediate the issue.

For European organizations, this vulnerability poses a risk primarily to end users who rely on the LINE iOS client for communication. The address bar spoofing can facilitate phishing attacks that may lead to credential compromise, unauthorized access to corporate resources, or the spread of malware through deceptive content. While the vulnerability does not directly affect system confidentiality or availability, the social engineering vector can indirectly lead to data breaches or financial fraud. Organizations with employees using LINE on iOS devices are at risk of targeted phishing campaigns exploiting this flaw. The impact is heightened in sectors with high reliance on mobile communications, such as finance, healthcare, and government. Additionally, the trust in LINE as a communication platform could be undermined, affecting user behavior and organizational communication policies. The lack of known exploits in the wild reduces immediate risk but does not eliminate the potential for future attacks. European organizations should consider this vulnerability in their mobile device management and security awareness programs.

1. Update the LINE client for iOS to version 14.14 or later as soon as the patch is available to eliminate the vulnerability. 2. Until patching is possible, implement mobile device management (MDM) policies to restrict the use of vulnerable LINE versions on corporate devices. 3. Educate users about the risks of phishing attacks, emphasizing caution when interacting with links inside the LINE app, especially those that open in the in-app browser. 4. Encourage users to verify URLs carefully and to use external browsers for sensitive transactions instead of the in-app browser. 5. Monitor network traffic and endpoint logs for suspicious activity that may indicate exploitation attempts, such as unusual iframe usage or unexpected JavaScript execution patterns. 6. Collaborate with IT and security teams to integrate LINE client usage into broader threat detection and response strategies. 7. Consider deploying endpoint protection solutions capable of detecting phishing and malicious scripts within mobile applications. 8. Review and update incident response plans to include scenarios involving mobile app-based phishing attacks.