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Old 09-09-2009, 01:04 AM   #1
Registered: Sep 2003
Location: Sydney Australia
Distribution: Redhat, Centos, Solaris, Ubuntu, SUSE
Posts: 282

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Question Squid Forwarding Loop


I'm not a squid guy, in actual fact I think I've ever only installed it once before, but anyway got this problem identified by a Nessus report

Squid can be put into a loop with itself. Causing DOS on system. Reconfigure squid to fix.

I'm using squid squid-2.5.STABLE14-1.4E.el4_6.2

From what I understand a Forwarding loop is when it can use itself to repeat the call.

Anyway would appreciate some help with making my config a little more secure to prevent this problem:

http_port 8080
hierarchy_stoplist cgi-bin ?
acl QUERY urlpath_regex cgi-bin \?
no_cache deny QUERY
auth_param basic children 5
auth_param basic realm Squid proxy-caching web server
auth_param basic credentialsttl 2 hours
auth_param basic casesensitive off
refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern . 0 20% 4320
acl all src
acl manager proto cache_object
acl localhost src
acl to_localhost dst
acl SSL_ports port 443 563
acl Safe_ports port 80 # http
acl Safe_ports port 21 # ftp
acl Safe_ports port 443 563 # https, snews
acl Safe_ports port 70 # gopher
acl Safe_ports port 210 # wais
acl Safe_ports port 1025-65535 # unregistered ports
acl Safe_ports port 280 # http-mgmt
acl Safe_ports port 488 # gss-http
acl Safe_ports port 591 # filemaker
acl Safe_ports port 777 # multiling http
acl SatSvr src
acl Mynet src
acl HKG src
http_access allow SatSvr
http_access allow Mynet
http_access allow HKG
http_access allow manager localhost
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow localhost
http_access deny all
http_reply_access allow all
icp_access allow all
coredump_dir /var/spool/squid

I think I need to use cache_peer_access rules to help prevent this but not entirely sure.

Thanks for any idea's..



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