SMTP smuggling (2023)
Timo Longin showed that outbound and inbound email servers parse message data differently, letting attackers smuggle extra content past security scanners. The technique affected major providers before patches landed.
Major mail providers deployed fixes for the parsing gaps.
The research established SMTP parsing discrepancies as a repeatable bug class and produced the techniques behind the iCloud findings.
Same researcher, same root cause: servers that interpret the same message differently. The iCloud flaws are the direct follow-on.
