[Japanese]

JVNDB-2021-000068

Multiple vulnerabilities in Retty App

Overview

Retty App provided by Retty Inc. contains multiple vulnerabilities listed below.
* The app is launched by Custom URL Scheme and a user may be led to access an arbitrary URL (CWE-939) - CVE-2021-20747
* The App uses a hard-coded API key for external services (CWE-798) - CVE-2021-20748

Ryo Sato of BroadBand Security,Inc. reported these vulnerabilities to IPA.
JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.
CVSS Severity (What is CVSS?)

CVSS V3 Severity:
Base Metrics 4.0 (Medium) [IPA Score]
  • Attack Vector: Local
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
  • Confidentiality Impact: Low
  • Integrity Impact: None
  • Availability Impact: None
CVSS V2 Severity:
Base Metrics 5.0 (Medium) [IPA Score]
  • Access Vector: Network
  • Access Complexity: Low
  • Authentication: None
  • Confidentiality Impact: Partial
  • Integrity Impact: None
  • Availability Impact: None
The above CVSS base scores have been assigned for CVE-2021-20748

CVSS V3 Severity:
Base Metrics: 4.3 (Medium) [IPA Score]
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: Required
  • Scope: Unchanged
  • Confidentiality Impact: None
  • Integrity Impact: Low
  • Availability Impact: None
CVSS V2 Severity:
Base Metrics: 4.3 (Medium) [IPA Score]
  • Access Vector: Network
  • Access Complexity: Medium
  • Authentication: None
  • Confidentiality Impact: None
  • Integrity Impact: Partial
  • Availability Impact: None
The above CVSS base scores have been assigned for CVE-2021-20747
Affected Products


Retty, INC.
  • Retty App for Android versions prior to 4.8.13
  • Retty App for iOS versions prior to 4.11.14

Impact

The expected impact depends on each vulnerability, but it may be affected as follows.
* 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 - CVE-2021-20747
* An attacker may analyze the data in the App and obtain the API key for external services - CVE-2021-20748
Note that the users are not directly affected by CVE-2021-20748 vulnerability.
Solution

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

According to the developer, in the fixed version the vulnerable API key (CVE-2021-20748) is inactivated, therefore the information contained in the vulnerable App is no longer compromised.
Vendor Information

Retty, INC.
CWE (What is CWE?)

  1. Permissions(CWE-264) [IPA Evaluation]
  2. No Mapping(CWE-Other) [IPA Evaluation]
CVE (What is CVE?)

  1. CVE-2021-20747
  2. CVE-2021-20748
References

  1. JVN : JVN#26891339
  2. National Vulnerability Database (NVD) : CVE-2021-20747
  3. National Vulnerability Database (NVD) : CVE-2021-20748
Revision History

  • [2021/07/13]
      Web page was published
  • [2023/03/08]
      Overview was modified

Date Public2021/07/13
Date First Published2021/07/13
Date Last Updated2023/03/08