Improper authorization in handler for custom URL scheme issue in "Mercari" App for Android prior to version 5.78.0 allows a remote attacker to lead a user to access an arbitrary website via the vulnerable App. As a result, the user may become a victim of a phishing attack.

Improper authorization in handler for custom URL scheme issue in "Mercari" App for Android prior to version 5.78.0 allows a remote attacker to lead a user to access an arbitrary website via the vulnerable App. As a result, the user may become a victim of a phishing attack.

"Mercari" App for Android by Mercari, Inc. provides the function to access a requested URL using Custom URL Scheme. The App does not restrict access to the function properly (CWE-939) which may be exploited to direct the App to access any sites. Shiga Takuma of BroadBand Security Inc. reported this vulnerability to IPA. JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.