CVE-2025-14019 is a vulnerability identified in the LINE client for Android, specifically affecting versions from 13.8 through 15.5. The issue is a UI spoofing flaw within the app's in-app browser component. The vulnerability arises when a specially crafted layout can obscure the full-screen warning prompt that normally alerts users when they are navigating away from the LINE app to an external web page. By hiding this security prompt, attackers can trick users into believing they remain within the trusted LINE environment, facilitating phishing attacks that could steal credentials or other sensitive information. The vulnerability requires no privileges and can be exploited remotely over the network, but it does require user interaction to trigger the malicious content. The CVSS 3.1 base score is 3.4, reflecting a low severity primarily due to the need for user interaction and the high attack complexity. The vulnerability impacts the integrity of the user interface and the trustworthiness of security prompts but does not directly compromise confidentiality or availability. No known exploits have been reported in the wild, and no official patches or updates have been linked at the time of publication. The vulnerability highlights the risks associated with in-app browsers and the importance of clear user interface cues to prevent phishing and social engineering attacks within mobile applications.

For European organizations, the primary impact of CVE-2025-14019 is an increased risk of phishing attacks targeting users of the LINE Android client. As LINE is widely used for both personal and business communication in some European countries, attackers could exploit this vulnerability to impersonate trusted entities and steal credentials or sensitive information. Although the vulnerability does not directly compromise system confidentiality or availability, successful phishing attacks can lead to broader security incidents such as account takeover, data breaches, or lateral movement within corporate networks. The requirement for user interaction and the high attack complexity reduce the likelihood of widespread exploitation, but targeted attacks against high-value individuals or organizations remain a concern. Organizations relying on LINE for communication should consider the risk of social engineering and implement controls to mitigate phishing threats. The absence of known exploits in the wild suggests the threat is currently low but could increase if attackers develop reliable exploit techniques.

To mitigate the risk posed by CVE-2025-14019, European organizations should take several specific actions beyond generic advice: 1) Educate users about the risks of phishing and the importance of verifying URL authenticity, especially when interacting with links inside the LINE app's in-app browser. 2) Encourage users to update the LINE client to versions beyond 15.5 once patches become available, or temporarily avoid using the in-app browser feature if possible. 3) Implement mobile device management (MDM) policies that restrict or monitor the use of in-app browsers within corporate environments. 4) Deploy advanced email and messaging security solutions that can detect and block phishing links before they reach users. 5) Monitor network traffic for suspicious activity related to LINE communications and in-app browser usage. 6) Promote multi-factor authentication (MFA) on accounts accessed via LINE to reduce the impact of credential theft. 7) Coordinate with LINE Corporation for timely patch deployment and vulnerability disclosure updates. These targeted measures will help reduce the likelihood and impact of phishing attacks exploiting this UI spoofing vulnerability.