.line
Mark EOF in qf file V8.7 and later
One form of attack against
sendmail involves appending
information to an existing qf
file. To prevent such attacks, V8.7
introduced the dot line. In a qf
file, any line that
begins with a single dot:
.followed by anything
is considered to mark the end of the file’s useful
information. Upon encountering that dot,
sendmail continues to read
the qf
file. If
any line follows the dot line,
sendmail logs the following
message and changes the qf
file into a Qf
file (Extra Data at End of qf File on page
420):
SECURITY ALERT: extra data in qf: bogus line here
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