[cups.bugs] [LOW] STR #3888: DoS checking misbehaves with unix socket

[Matt L]

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[STR New]

DoS checking in the client code appears to misbehave when connections come
from a local unix socket.

First, this appears to be the cause of http://www.cups.org/str.php?L3716
where the error "Possible DoS attack from .." shows no responsible IP
address.  Preliminary testing seems to show that httpAddrString is not
returning anything usable for connections from the unix socket.

Furthermore this seems to indicate that the DoS checking mechanism could
be triggered by connections coming from a busy local machine (in our case
running Samba).  It seems illogical to claim a DoS attack coming from
localhost, as blocking the localhost will not produce any positive results
for the remaining users.  Whereas blocking a single abusive remote IP will
free up resources for additional remote users, blocking the local machine
will block all users accessing via Samba or some other mechanism.

Link: http://www.cups.org/str.php?L3888
Version: 1.4.7