I just received an email that crashed halted fetchmail/sendmail on my
machine. Fetchmail just sat there trying to deliver the message forever. On
inspection of the message using Yahoo mail, I found it to contain random
data, that looks like some sort of buffer overflow attack, followed by
machine code. It also contains a binary picture. The mail seems to be called
"Love Days" and has a faulty header. The MAIL FROM:
wherever(_at_)wherever(_dot_)com
field is immediately followed on the same line by SIZE: 4532. This is where
fetchmail halts waiting for sendmail to accept it. Sendmail continues to work
fine for all other mail operations, it's only the fetchmail process that's
halted. A fix could be done immediately by making fetchmail handle the broken
header, and deliver it anyway. I forgot to save a copy of the mail, so I
can't find out what it does to windows clients, but that is outside the scope
of fetchmail. Fetchmail only needs to deliver messages reliably to the MTA.
Thanks,
David
P.S. Please CC a copy of your response directly to me, thanks