Early 2021, Kaspersky’s researchers, upon further analysis into the already reported CVE-2021-1732 exploit used by the BITTER APT group, have managed to discover another zero-day exploit. The experts are currently unable to link this exploit to any known threat actor.
A zero-day vulnerability is basically an unknown software bug. Upon identification and discovery, they allow attackers to conduct malicious activities in the shadows, resulting in unexpected and destructive consequences. While analyzing the CVE-2021-1732 exploit, Kaspersky experts found another such zero-day exploit and reported it to Microsoft in February. After confirmation that it is indeed a zero-day, it received the designation CVE-2021-28310.