Full Disclosure mailing list archives
Re: Proxies
From: Ben Nelson <venom () venom600 org>
Date: Fri, 31 Oct 2003 11:06:12 -0700
Blocking all internal->external traffic and then allowing ONLY the needed services from the necessary hosts is the best way to stop this sort of abuse. Then, using a web proxy that filters web content and only understands HTTP (to prevent other services from being tunneled over port 80), you should be good to go.
--Ben Earl Keyser wrote:
Help needed, please. We use all cisco networking gear. Currently using a cisco cache engine with SmartFilter to "manage" the surfing for our staff/students. Asusual, the little devils figured a way to get around it.They went to Google, entered "open proxy list" and bingo-bango. From this list they found open proxies to use in IE. Besides suspending them, we made one technological change. Outgoing ports 8000, 8080, 8888 and 3128 are now blocked at the firewall. Can anyone suggest further refinements to reduce this kind of abuse? I know some proxies run on port 80, but I'll have to live with that. TIA Earl Earl Keyser, Network Specialist Wayzata Public Schools 763-745-5105 "Unix IS user-friendly. It's just picky about who its friends are." This outbound message has been scanned for viruses by ISD#284. _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.netsys.com/full-disclosure-charter.html
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Current thread:
- Proxies Earl Keyser (Oct 31)
- Re: Proxies Jan Meijer (Oct 31)
- Re: Proxies Ben Nelson (Oct 31)
- Re: Proxies Gary E. Miller (Oct 31)
- Re: Proxies nosp (Oct 31)
- Re: Proxies Charles E. Hill (Oct 31)
- Re: Proxies Valdis . Kletnieks (Oct 31)
- Re: Proxies Ben Nelson (Oct 31)
- Re: Proxies Richard Spiers (Oct 31)
- RE: Proxies adam.richards (Oct 31)
- Re: Proxies Ben Nelson (Oct 31)
- Re: Proxies Richard Spiers (Oct 31)
- Re: Proxies Jakob Lell (Oct 31)
- <Possible follow-ups>
- RE: Proxies Bassett, Mark (Oct 31)
- RE: Proxies S G Masood (Oct 31)