linuxdcpp-team team mailing list archive

[RoLex <2019497@xxxxxxxxxxxxxxxxxx>]

The ability to flood and even crash clients have been there for a very
long time, because the client itself does not implement any kind of
flood protection, except the search flood. I guess that clients mostly
rely on hub antiflood protection, but in this case it is a hub itself
that enforces the flood.

I have written antiflood Lua script in 2014 for ApexDC++ that I used to
run, it requires Scripts plugin, and works well on any client that
supports latest Scripts plugin, inclusive DC++:

https://ledo.feardc.net/dcpp/antiflood.lua

-- 
You received this bug notification because you are a member of
Dcplusplus-team, which is subscribed to DC++.
https://bugs.launchpad.net/bugs/2019497

Title:
  Handling of CTM/search DDoS triggered by a malicious hub

Status in AirDC++:
  Fix Released
Status in DC++:
  Confirmed

Bug description:
  I've received a few weird crash reports that are both linked to a
  specific hub (favorite-hub.net):

  https://github.com/airdcpp-web/airdcpp-webclient/issues/450
  https://github.com/airdcpp/airdcpp-windows/issues/63

  While inspecting the issue more closely, I noticed that the client
  receives about 300 search/CTM requests per second from the hub,
  similar to these:

  $Search 82.146.38.183:80 F?F?0?1?t
  $ConnectToMe maksis 82.146.38.183:443
  $Search 82.146.38.183:443 F?F?0?1?p
  $ConnectToMe maksis 82.146.38.183:80
  $Search 82.146.38.183:80 F?F?0?1?t
  $ConnectToMe maksis 82.146.38.183:443
  $Search 82.146.38.183:443 F?F?0?1?p
  $ConnectToMe maksis 82.146.38.183:80
  $Search 82.146.38.183:80 F?F?0?1?t
  $ConnectToMe maksis 82.146.38.183:443

  Looks like this has been going on for years already and the client is
  unable to even report it in a meaningful way. DC++ shows a few status
  messages about search spam but that doesn't really reveal the full
  extent of the problem as the aim of the hub is clearly to consume all
  possible system resources from its users.

To manage notifications about this bug go to:
https://bugs.launchpad.net/airdcpp/+bug/2019497/+subscriptions