The CyberAgent Ameba application 3.x and 4.x before 4.5.0 for Android does not verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.
https://www.cyberagent.co.jp/info/detail/id=9185
https://play.google.com/store/apps/details?id=jp.ameba