CVE-2025-14019 identifies a UI spoofing vulnerability in the LINE client for Android versions 13.8 through 15.5. The vulnerability arises within the in-app browser component, where a specifically crafted layout can obscure the full-screen warning prompt that normally alerts users when they are navigating away from the app or visiting external links. This UI manipulation can mislead users into believing they are interacting with legitimate LINE interface elements, thereby facilitating phishing attacks. The vulnerability is classified under CWE-451 (User Interface Misrepresentation). The CVSS v3.1 base score is 3.4, indicating low severity, with vector AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:L/A:N. This means the attack can be launched remotely over the network without privileges but requires user interaction and has a high attack complexity. The scope is changed (S:C), indicating that the vulnerability affects components beyond the initially vulnerable component, potentially impacting the entire application context. The impact is limited to integrity, as attackers could trick users into disclosing sensitive information or performing unintended actions, but there is no direct confidentiality or availability impact. No patches or exploits are currently reported, but the vulnerability is publicly disclosed as of December 15, 2025. The lack of a patch means users remain exposed until an update is released by LINE Corporation.

For European organizations, the primary risk posed by CVE-2025-14019 is the potential for phishing attacks leveraging UI spoofing within the LINE Android app's in-app browser. This could lead to unauthorized disclosure of credentials or sensitive information if users are deceived by the obscured warning prompts. While the vulnerability does not directly compromise system confidentiality or availability, the social engineering vector could facilitate further attacks such as account takeover or lateral movement if credentials are harvested. Organizations relying heavily on LINE for internal or external communications, especially in sectors like finance, healthcare, and government, may face increased risk. The impact is mitigated somewhat by the requirement for user interaction and the high attack complexity, but the widespread use of LINE in Europe means a significant user base could be targeted. Additionally, the vulnerability's scope change suggests that the entire app context could be affected, increasing the potential attack surface. The absence of known exploits reduces immediate risk but does not eliminate the threat of future exploitation.

1. Monitor LINE Corporation announcements for official patches addressing CVE-2025-14019 and apply updates promptly once available. 2. Until patches are released, restrict the use of the LINE in-app browser for accessing sensitive or untrusted links by configuring organizational policies or educating users to open links in external browsers. 3. Conduct targeted user awareness training focusing on recognizing suspicious UI elements and the importance of heeding full-screen warning prompts within apps. 4. Implement mobile device management (MDM) solutions to enforce app update policies and control app permissions related to network and browser usage. 5. Encourage the use of multi-factor authentication (MFA) on LINE accounts to reduce the impact of credential compromise resulting from phishing. 6. Monitor network traffic and endpoint logs for unusual activity related to LINE app usage that could indicate phishing attempts or exploitation. 7. Collaborate with security teams to simulate phishing scenarios involving in-app browser spoofing to improve detection and response capabilities.