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[Full-disclosure] Advisory

Hello 


Please find attached two advisories for your lists.

Should you have any queries please do not hesitate to contact me.


Kind Regards



Tracey Parry 

Portcullis Computer Security Ltd 


Telephone Number: 020 8868 0098


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Portcullis Security Advisory - 08-009


Vulnerable System:

Checkpoint VPN-1


Vulnerability Title:

Checkpoint VPN-1 PAT information disclosure.


Vulnerability Discovery And Development:

Portcullis Security Testing Services.


Credit For Discovery:

Tim Brown and Mark Lowe - Portcullis Computer Security Ltd.


Affected systems:

All known versions of Checkpoint VPN-1; the vulnerability discovered was for 
version R65.


Details:

By sending crafted packets to ports on the Firewall which are mapped by port 
address translation (PAT) to ports on internal devices, information about the 
internal network may be disclosed in the resulting ICMP error packets. Port 
18264/tcp on the Firewall is typically configured in such a manner, with 
packets to this port being re-written to reach the Firewall management server. 
When the time-to-live (TTL) is set low, the Firewall fails to correctly 
sanitise the encapsulated IP headers in ICMP time-to-live exceeded packets 
resulting in the internal IP address being disclosed. For example:

The response was elicited by sending a packet (from 194.0.0.1) to port 
18264/tcp on the Firewall's interface. The TTL was set low, so the Firewall 
could not forward it on.

14:56:25.169480 IP (tos 0xe0, ttl 255, id 21407, offset 0, flags [none], proto: 
ICMP (1), length: 68) 193.0.0.1 > 194.0.0.1: ICMP time exceeded in-transit, 
length 48
IP (tos 0x0, ttl 1, id 5120, offset 0, flags [none], proto: TCP (6), length: 
40) 194.0.0.1.9003 > 10.0.0.99.18264: S, cksum 0x03e6 (correct), 
2834356043:2834356043(0) win 512

The destination address on the encapsulated IP packet is the address of the 
Firewall management server. Note: This can be exploited whether the port is 
detected as being open or closed by a port scan of the Firewall's interface.


Impact:

An attacker could use this to determine the internal IP address of the Firewall 
management server.


Exploit:

The proof of concept exploit code is available as a NASL plugin for OpenVAS.


Vendor Status:

11/09/2008 - Vendor informed via email.
23/09/2008 - Vendor Informed via email.
24/10/2008 - Vendor informed of publication intention


Copyright:

Copyright � Portcullis Computer Security Limited 2008, All rights reserved 
worldwide.
Permission is hereby granted for the electronic redistribution of this 
information. It is not to be edited or altered in any way without the express 
written consent of Portcullis Computer Security Limited.


Disclaimer:

The information herein contained may change without notice. Use of this 
information constitutes acceptance for use in an AS IS condition. There are NO 
warranties, implied or otherwise, with regard to this information or its use. 
Any use of this information is at the user's risk. In no event shall the 
author/distributor (Portcullis Computer Security Limited) be held liable for 
any damages whatsoever arising out of or in connection with the use or spread 
of this information.

Portcullis Security Advisory - 08-010


Vulnerable System:

Microsoft Windows Active Directory LDAP Server


Vulnerability Title:

Microsoft Windows Active Directory LDAP Server Information Disclosure 
Vulnerability


Vulnerability Discovery And Development:

Portcullis Security Testing Team


Credit For Discovery:

Bernardo Damele Assumpcao Guimaraes - Portcullis Computer Security Ltd


Affected systems:

Microsoft Windows 2000 Server Service Pack 4
Microsoft Windows Server 2003 Service Pack 1
Microsoft Windows Server 2003 Service Pack 2


Details:

An information disclosure vulnerability exists in the manner that Microsoft 
LDAP server responds when binding to the LDAP server. In the case when an 
invalid password is provided, the server will respond with result code 49 
(invalidCredentials) and an error message.  A different error message is 
returned if an invalid username is provided.

For an existing user the bind response is similar to:
80090308: LdapErr: DSID-0C090334, comment: AcceptSecurityContext error, data 
52e, vece

For an non-existant user the following error message is returned:
80090308: LdapErr: DSID-0C090334, comment: AcceptSecurityContext error, data 
525, vece

As you can see, the values 52e and 525 differ. The meaning associated to 52e is 
'invalid credentials'.  The meaning associated to 525 is 'user not found'. The 
server can respond with seven other error codes, which makes it possible to 
infer other information about the status of the account such as "account has 
expired" or "user account locked".


Impact:

A successful exploit of this issue can allow an attacker to anonymously 
enumerate users on the affected system.


Exploit:

An exploit is available at 
http://labs.portcullis.co.uk/application/ldapuserenum/


Vendor Response and Recomendations:

Block TCP ports 389 and 636 at the perimeter firewall.

These ports are used to initiate a connection with the affected component.
Blocking it at the enterprise firewall, both inbound and outbound, will help 
prevent systems that are behind that firewall from attempts to exploit this 
vulnerability. We recommend that you block all unsolicited inbound 
communication from the Internet to help prevent attacks that may use other 
ports. For more information about ports, see TCP and UDP Port Assignments 
(http://go.microsoft.com/fwlink/?LinkId=21312). For more information about the 
Windows Firewall, see How to Configure Windows Firewall on a Single Computer 
(http://www.microsoft.com/technet/security/smallbusiness/prodtech/windowsxp/cfgfwall.mspx).


Timeline:

2008/10/06 - Vulnerability discovered
2008/10/21 - Internal proof of concept ready
2008/10/23 - Advisory draft ready
2008/10/24 - Initial notification to the vendor
2008/10/28 - Vendor acknowledges notification, case opened
2008/11/05 - Vendor reproduced the issue and the bug fix will be addressed 
through a Service Pack release
2008/11/07 - Vendor asks to add a mitigations section to the advisory
2008/11/11 - Portcullis adds a Vendor Response and Recomendations section
2008/11/13 - Advisory published in accordance with the vendor


Copyright:

Copyright © Portcullis Computer Security Limited 2008, All rights reserved 
worldwide.
Permission is hereby granted for the electronic redistribution of this 
information. It is not to be edited or altered in any way without the express 
written consent of Portcullis Computer Security Limited.


Disclaimer:

The information herein contained may change without notice. Use of this 
information constitutes acceptance for use in an AS IS condition. There are NO 
warranties, implied or otherwise, with regard to this information or its use. 
Any use of this information is at the user's risk. In no event shall the 
author/distributor (Portcullis Computer Security Limited) be held liable for 
any damages whatsoever arising out of or in connection with the use or spread 
of this information.

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