Japanese telecommunications operator KDDI Corporation disclosed a data breach where threat actors gained access to one of its email systems used by five other internet service providers (ISPs) in the country.
The company says that it discovered the compromise on June 17 and responded immediately by blocking the attacker and implementing defense measures.
The investigation determined that the hackers exploited a vulnerability in an unnamed third-party software that KDDI Corporation used on its system.
“Although technical defensive measures have already been implemented for the system, there remains a possibility that customers' email addresses and passwords were obtained by unauthorized third parties as a result of the incident,” KDDI warns.
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