Published:2021/04/14  Last Updated:2023/03/08

JVN#54025691
Gurunavi Apps fail to restrict access permissions

Overview

Gurunavi Apps fail to restrict access permissions.

Products Affected

  • Gurunavi App for Android ver.10.0.14 and earlier
  • Gurunavi App for iOS ver.11.2.3 and earlier
【Updated on 2021 May 24】
When this advisory was first published on 2021 April 14, the affected versions were described as "Gurunavi App for Android ver.10.0.10 and earlier" and "Gurunavi App for iOS ver.11.1.2 and earlier".  However, it was found that the fixes were not adequate, thus above versions that contain the fixes were released later.

Description

Gurunavi Apps provided by Gurunavi, Inc. implement the function to access a requested URL using Custom URL Scheme.
This function contains an improper access control vulnerability (CWE-284) that may allow the vulnerable App to receive an request from an arbitrary App and execute an access.

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 Status Last Update Vendor Notes
Gurunavi, Inc. Vulnerable 2021/05/20

References

JPCERT/CC Addendum

Vulnerability Analysis by JPCERT/CC

CVSS v3 CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
Base Score: 3.3
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
Base Score: 4.3
Access Vector(AV) Local (L) Adjacent Network (A) Network (N)
Access Complexity(AC) High (H) Medium (M) Low (L)
Authentication(Au) Multiple (M) Single (S) None (N)
Confidentiality Impact(C) None (N) Partial (P) Complete (C)
Integrity Impact(I) None (N) Partial (P) Complete (C)
Availability Impact(A) None (N) Partial (P) Complete (C)

Credit

Ryo Sato of BroadBand Security,Inc. reported this vulnerability to IPA.
JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.

Other Information

JPCERT Alert
JPCERT Reports
CERT Advisory
CPNI Advisory
TRnotes
CVE CVE-2021-20693
JVN iPedia JVNDB-2021-000031

Update History

2021/05/24
Gurunavi, Inc. update status
2021/05/24
Information under [Products Affected] was updated.
2023/03/08
Information under the section [Credit] was updated.