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
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.
References
JPCERT/CC Addendum
Vulnerability Analysis by JPCERT/CC
| 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) |
| 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.