CVE-2024-41918 in Ichiba App
Summary
by MITRE • 08/29/2024
'Rakuten Ichiba App' for Android 12.4.0 and earlier and 'Rakuten Ichiba App' for iOS 11.7.0 and earlier are vulnerable to improper authorization in handler for custom URL scheme. An arbitrary site may be displayed on the WebView of the product via Intent from another application installed on the user's device. As a result, the user may be redirected to an unauthorized site, and the user may become a victim of a phishing attack.
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Analysis
by VulDB Data Team • 03/12/2025
The vulnerability identified as CVE-2024-41918 affects the Rakuten Ichiba mobile applications across both Android and iOS platforms, specifically versions 12.4.0 and earlier for Android and 11.7.0 and earlier for iOS. This security flaw resides in the application's handling of custom URL schemes, which are mechanisms that allow different applications to communicate and share data through predefined protocols. The vulnerability stems from inadequate authorization checks within the URL handling mechanism, creating a pathway for malicious actors to exploit the application's WebView component through external intents.
The technical implementation of this vulnerability involves the improper validation of incoming intents that contain custom URLs. When the Rakuten Ichiba application receives an intent through a custom URL scheme, it fails to properly verify the source or validate the URL content before rendering it within its WebView component. This allows any application installed on the user's device to send a specially crafted intent that triggers the WebView to load arbitrary content from external domains. The flaw essentially bypasses the application's intended security boundaries and creates an attack vector where malicious applications can manipulate the user interface to display unauthorized content.
From an operational perspective, this vulnerability creates significant risk for users of the Rakuten Ichiba application as it enables sophisticated phishing attacks. When an attacker crafts a malicious intent and sends it to the vulnerable application, the user may be unknowingly redirected to a fraudulent website that mimics legitimate Rakuten services. The WebView component, which is designed to display web content within the application, becomes a conduit for malicious content delivery. Users may be tricked into entering sensitive information such as login credentials, personal details, or financial data, believing they are interacting with legitimate Rakuten services. The attack requires no special privileges or root access on the device, making it particularly dangerous as it can be executed by any application with the ability to send intents to the Rakuten Ichiba application.
The security implications of this vulnerability extend beyond simple phishing attacks and can be categorized under CWE-284, which addresses improper access control in software systems. This weakness allows unauthorized access to application resources through improper authorization mechanisms. Additionally, the vulnerability aligns with ATT&CK technique T1566, which covers phishing attacks through malicious intent delivery, and T1071.004, which addresses application layer protocols involving web services. The attack surface is particularly concerning because it leverages the Android Intent system, which is designed for legitimate inter-application communication but becomes a security risk when proper validation is absent. The vulnerability also demonstrates poor input validation practices, similar to CWE-20, where applications fail to properly sanitize and validate external inputs before processing them.
Mitigation strategies for this vulnerability should focus on implementing proper intent validation and authorization checks within the application's URL handling mechanism. Developers should enforce strict validation of incoming intents, ensuring that only trusted sources can trigger WebView content loading. This includes implementing source verification, URL sanitization, and content filtering mechanisms that prevent arbitrary content from being displayed. The application should also implement proper sandboxing of WebView components and consider using more secure communication methods such as HTTPS with certificate pinning. Additionally, implementing proper access controls and restricting the ability of external applications to send intents to the vulnerable application would significantly reduce the attack surface. Regular security audits and penetration testing should be conducted to identify similar authorization flaws in other components of the application, and developers should follow secure coding practices that emphasize input validation and proper access control mechanisms.