Yuko Yuko App for Android fails to verify SSL server certificates


Yuko Yuko App for Android provided by Yuko Yuko Corporation fails to verify SSL server certificates.

Shunsuke Taniguchi of LAC Co., Ltd. reported this vulnerability to IPA.
JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.
CVSS Severity (What is CVSS?)

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

Yuko Yuko Corporation
  • Yuko Yuko App for Android versions 1.0.5 and earlier


A man-in-the-middle attack may allow an attacker to eavesdrop on an encrypted communication. As a result, an attacker may obtain information entered into web forms.

[Update the Software]
Update to the latest version according to the information provided by the developer.
Vendor Information

Yuko Yuko Corporation
CWE (What is CWE?)

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

  1. CVE-2014-5323

  1. JVN : JVN#04560253
Revision History

  • [2014/09/22]
      Web page was published