MFH: r454936

• Fix RCE vulnerability:

The receive_msg function in receive.c in the SMTP daemon in Exim 4.88 and 4.89
allows remote attackers to execute arbitrary code or cause a denial of service
(use-after-free) via vectors involving BDAT commands.

PR: 223870
Submitted by: Gary
Security: 68b29058-d348-11e7-b9fe-c13eb7bcbf4f

Approved by: ports-secteam (swills)