JVN#38034268: あすけん App for Android fails to restrict custom URL schemes properly

Overview

あすけん App for Android fails to restrict custom URL schemes properly.

Products Affected

あすけん App for Android versions from v.3.0.0 to v.4.2.x

Note that あすけん App is only available in Japan.

Description

あすけん App for Android by asken 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.

Impact

A remote attacker may 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.

Solution

Update the Application
Update the application to the latest version according to the information provided by the developer.

Vendor Status

Vendor	Link
asken Inc.	あすけんダイエット (asken diet) \| Notification (Text in Japanese, login required)

References

JPCERT/CC Addendum

Vulnerability Analysis by JPCERT/CC

CVSS v3 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Base Score: 4.3

Attack Vector(AV)	Physical (P)	Local (L)	Adjacent (A)	Network (N)
Attack Complexity(AC)	High (H)	Low (L)
Privileges Required(PR)	High (H)	Low (L)	None (N)
User Interaction(UI)	Required (R)	None (N)
Scope(S)	Unchanged (U)	Changed (C)
Confidentiality Impact(C)	None (N)	Low (L)	High (H)
Integrity Impact(I)	None (N)	Low (L)	High (H)
Availability Impact(A)	None (N)	Low (L)	High (H)

CVSS v2 AV:N/AC:M/Au:N/C:N/I:P/A:N