Apple’s response (emphasis mine):
In response to the report, an Apple spokesperson said “security researchers agree that iPhone is the most secure consumer mobile device, and we work tirelessly every day to protect all our users from new and emerging threats.”
“We sympathize with users who have had this experience and we take all attacks on our users very seriously, no matter how rare,” the spokesperson added. “We will continue to advance the protections to help keep user accounts secure.” Apple did not provide any specific details about any next steps it might take to increase security.