Versions mentioned in the description apply to the upstream
Remediation section below for
Debian:9 relevant versions.
Exim 4 before 4.94.2 allows Integer Overflow to Buffer Overflow in receive_add_recipient via an e-mail message with fifty million recipients. NOTE: remote exploitation may be difficult because of resource consumption.
exim4 to version 4.89-2+deb9u8 or higher.