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Raptor 6.5 http vulnerability

daemon@ATHENA.MIT.EDU (Lysel Christian Emre)
Mon Mar 26 02:14:16 2001

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Message-ID:  <F117D97CF18AD3119A5240008308566A10EC9B@WMSI000273>
Date:         Sat, 24 Mar 2001 17:55:29 +0100
Reply-To: Lysel Christian Emre <chlys@WMDATA.COM>
From: Lysel Christian Emre <chlys@WMDATA.COM>
X-To:         "raptor-list@firetower.com" <raptor-list@firetower.com>
To: BUGTRAQ@SECURITYFOCUS.COM

1. Problem Description

	The Raptor firewall is vulnerability for forwarding http
	request on other port numbers than 80, if a rule allows http
	traffic.

	Redirect rules does not affect this problem.

	When an extern or internal client, configures itself to use
	the nearest interface as proxy, it's possible to access other
	ports that 80 on the target host.

	Only the http protocol is allowed and only to a range of TCP
	ports:

		TCP, 79-99 and TCP, 200-65535.

	If a port outside this range is targeted, an Alert
	will be issued.

	An example of what is vulnerability could be used for:

		Setting a Raptor firewall up, allowing Universe to
		access a local web server (host: webserver), listening
		on port 80 (normal website) and 2000 (admin
		site). This would give external users access to the
		admin site listening on port 2000, if the client is
		configured to use the external interface as a proxy
		server (for lynx: "export http_proxy =
		http://external-interface:80/ ; lynx
		http://webserver:2000/").
	
	This works not only for external users, but also for internal
	users.

	Testing of the Secure Socket Layer has not been performed.



2. Vulnerable Versions

	Raptor firewall 6.5.

2.1 Non Vulnerable Versions

	Raptor firewall 6.0.2.
	Older versions, not tested.

3. Solution

	1. Use httpd.noproxy in the affected rule.

	2. Downgrade to version 6.0.2

	3.  Apply hotfix SG6500-20000920-00 and SG6500-20001121-00,
	
ftp://ftp.axent.com/pub/RaptorFirewall/Patches/6.50/Internal/http-int.zip

	  Hot Fix SG6500-20000920-00 9/20/2000

	  if client uses firewall as proxy, firewall will forward
	  request to ports other than 80 on server. this vulnerability
	  is fixed by closing all ports for proxy except 80 and port
	  specified by httpd.allow_proxy_to_port_xxx=1.

	  Hot Fix SG6500-20001121-00 11/21/2000

	  this hotfix removes the implementation of
	  httpd.allow_proxy_to_port_xxx.  Without this implementation,
	  firewall could be used as proxy to access (inbound and
	  outbound) http ports other than 80.

3.1 Workaround:

	1. Disable the http proxy, and use the TCP proxy. But this
	will introduce other security concerns.

	2. Disable other listeners at the webserver.


4. References

	Found by:

	Benny Amorsen, benny_amorsen@hp.com and
	Christian E. Lysel, chlys@wmdata.com

	Reported to Axent the 29th Aug 2000.

--
Christian E. Lysel, Senior Security Consultant,
WM-data Infra Solutions eCom, Lautrupvang 10, DK - 2750 Ballerup
Phone +45 44 78 40 00, Mob +45 44 78 40 29, Fax +45 44 78 40 04

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