Versions mentioned in the description apply to the upstream
Remediation section below for
Debian:9 relevant versions.
Exim 4 before 4.94.2 allows Heap-based Buffer Overflow because it mishandles "-F '.('" on the command line, and thus may allow privilege escalation from any user to root. This occurs because of the interpretation of negative sizes in strncpy.
exim4 to version 4.89-2+deb9u8 or higher.