[Resolved][Severity: Critical][Web app exploit]

Imagineer: the management server of the Rilakkuma fan site Itsudemo Rilakkuma was accessed without authorization, and 105,180 mail addresses of free members leaked

A system weakness was exploited on December 29 and 30, 2020, and mail addresses given at free registration were stolen. They were registered between 2014 and January 2020.

Disclosed

2021-01-05

Organizations involved

Leaked or at risk

105.2K

105,180

Downtime

Unknown

What happened

2020-12-29
From this day to the 30th, the server that manages the site was accessed through a weakness. [1] [2]
2020-12-30
The company detected abnormal access to the management server and confirmed through investigation that mail addresses had leaked. It identified the attacking IP address and blocked it, and fixed the weakness. [1] [2]
2021-01-05
It began telling affected members what happened by mail and apologizing, and reported to the Personal Information Protection Commission and the Metropolitan Police. [1] [2]

Impact

The leak may cover 105,180 of the mail addresses used for free membership registration between March 18, 2014 and January 19, 2020. No leak of other data has been reported. The company said its measures to prevent a recurrence were already done. [1] [2]