"Jiyu Kukan Toku-Toku coupon" App vulnerable to improper server certificate verification


"Jiyu Kukan Toku-Toku coupon" App provided by RUNSYSTEM CO.,LTD. is vulnerable to improper server certificate verification (CWE-295).

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

CVSS V3 Severity:
Base Metrics 6.5 (Medium) [IPA Score]
  • Attack Vector: Network
  • Attack Complexity: High
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
  • Confidentiality Impact: High
  • Integrity Impact: Low
  • Availability Impact: None
CVSS V2 Severity:
Base Metrics 4.0 (Medium) [IPA Score]
  • Access Vector: Network
  • Access Complexity: High
  • Authentication: None
  • Confidentiality Impact: Partial
  • Integrity Impact: Partial
  • Availability Impact: None
Affected Products

  • Jiyu Kukan Toku-Toku coupon App for iOS versions 3.5.0 and earlier
  • Jiyu Kukan Toku-Toku coupon App for Android versions 3.5.0 and earlier


A man-in-the-middle attack may allow an attacker to eavesdrop on an encrypted communication.

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

[Apply the workaround]
Applying the following workarounds may mitigate the impacts of this vulnerability.

* Use the application while connected to the carrier's network or a trusted Wi-Fi access point
Vendor Information

CWE (What is CWE?)

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

  1. CVE-2023-29501

  1. JVN : JVN#33836375
  2. National Vulnerability Database (NVD) : CVE-2023-29501
Revision History

  • [2023/06/01]
      Web page was published
  • [2024/05/23]
      References : Content was added