Re: SNI-26: Ascend Router Security Issues

[twiggy () twiggy spider org (Cyril Jaouich)]

This is about the UDP bug found in Ascend products:

        The fix posted by Ascend works but is not perfect, since it ONLY
works for IP traffic. If you put this filter on your Ethernet interface,
arp messages will stop being processed. This is caused by the second
filter condition that lets ONLY Ip thru. Below is the correct filter, it
is also good to put in the Output filter I've made.

        Thanks

-----------------------
90-501 UDP Attack
-----------------
 In filter 01
> Valid =Yes
  Type = IP
  Generic...
  IP...

 Ip...
> Forward = No
  Src Mask = 0.0.0.0
  Src Adrs = 0.0.0.0
  Dst Mask = 0.0.0.0
  Dst Adrs = 0.0.0.0
  Protocol = 17
  Src Port Cmp = None
  Src Port # = N/A
  Dst Port Cmp = Eql
  Dst Port # = 9
  TCP Estab = N/A
--
 In filter 02
> Valid =Yes
  Type = GENERIC
  Generic...
  IP...

 Generic...

> Forward=Yes
  Offset=0
  Length=0
  Mask=0000000000000000
  Value=0000000000000000
  Compare=Equals
  More=No
-----------------
 Out filter 01
> Valid =Yes
  Type = IP
  Generic...
  IP...

 Ip...
> Forward = No
  Src Mask = 0.0.0.0
  Src Adrs = 0.0.0.0
  Dst Mask = 0.0.0.0
  Dst Adrs = 0.0.0.0
  Protocol = 17
  Src Port Cmp = None
  Src Port # = N/A
  Dst Port Cmp = Eql
  Dst Port # = 9
  TCP Estab = N/A
--
 Out filter 02
> Valid =Yes
  Type = GENERIC
  Generic...
  IP...

 Generic...

> Forward=Yes
  Offset=0
  Length=0
  Mask=0000000000000000
  Value=0000000000000000
  Compare=Equals
  More=No
-----------------

Cyril Jaouich [CJ837]
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ACC DATA OPERATIONS EASTERN CANADA
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