BugTraq
ESA-2010-015: EMC Celerra NFS authentication bypass vulnerability using IP spoofing. Sep 08 2010 09:03PM
Security_Alert emc com
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ESA-2010-015: EMC Celerra NFS authentication bypass vulnerability using IP

spoofing.

EMC Identifier: ESA-2010-015

CVE Identifier: CVE-2010-2860

Severity Rating: CVSS v2 Base Score: 8.3 (AV:A/AC:L/Au:N/C:C/I:C/A:C)

Affected products:

EMC SW: NAS Code 5.6.50 and earlier

Vulnerability Summary:

A vulnerability exists in EMC Celerra which can be exploited to gain

unauthorized access to root NFS export on EMC Celerra NAS.

Vulnerability Details:

A vulnerability in EMC Celerra may allow an attacker to spoof IP addresses

that are normally used between the Celerra Control Station and X-Blade

(Data Mover) over a private IP network. While these IP addresses are

normally intended for communication internal to the Celerra, they are also

accepted from external sources. By spoofing these IP addresses, an attacker

may be able to gain unauthorized access to file systems on the Celerra. The

vulnerability only exists when the attacker and external IP of the Data

Mover are on the same subnet.

Problem Resolution:

The following EMC Celerra products contain resolutions to this issue:

? EMC Celerra NAS Code 5.6.51

EMC strongly recommends all customers apply the latest patch, which

contains the resolution to this issue, at the earliest opportunity.

Link to remedies:

Registered EMC Powerlink customers can download software from Powerlink.

For Celerra Software, navigate in Powerlink to Home > Support > Software

Downloads and Licensing > Downloads C > Celerra Software.

Because the view is restricted based on customer agreements, you may not

have permission to view certain downloads. Should you not see a software

download you believe you should have access to, follow the instructions in

EMC Knowledgebase solution emc116045.

Workaround:

1. Create IP-based access rules on the network equipment rejecting traffic

for IP addresses belonging to the internal Celerra network. These addresses

are listed in the /etc/hosts file of the Celerra Control Station. That

traffic should never be routed to the Control Station; the traffic remains

internal to the cabinet and has its own network switches for that purpose.

2. Configure firewalls between Data Movers and NFS clients to reject

traffic for IP addresses belonging to the internal Celerra network.

3. Hide the Data Mover's NFS exports from clients that do not have access

by setting the forceFullShowmount parameter to 0 (default is 1). This will

hide the " / " from the list since only the Control Station has access to

it (for administrative purposes).

4. Disable IP reflect.

5. Change the default IP addresses for the internal network of the Celerra

to a non-routable IP address scheme that does not conflict with any other

non-routable IP networks.

To implement Step 3 above, modify the forceFullShowmount parameter as

follows:

[root@virgil slot_3]# server_param server_3 -f mount -info

forceFullShowmount

server_3 :

name = forceFullShowmount

facility_name = mount

default_value = 1

current_value = 1

configured_value =

user_action = none

change_effective = immediate

range = (0,1)

description = Forces response to showmount requests to fully

populate response.

[root@virgil slot_3]# server_param server_3 -f mount -modify forceFullShowmount -value 0

server_3 : done

After the above change, client will see only the shares he has permissions

to access to.

For explanation of Severity Ratings, refer to EMC Knowledgebase solution

emc218831.

Credits:

EMC would like to thank Steve Ocepek of Trustwave's SpiderLabs for

reporting this issue.

EMC Corporation distributes EMC Security Advisories in order to bring to

the attention of users of the affected EMC products important security

information. EMC recommends all users determine the applicability of this

information to their individual situations and take appropriate action. The

information set forth herein is provided "as is" without warranty of any

kind. EMC disclaims all warranties, either express or implied, including

the warranties of merchantability, fitness for a particular purpose, title

and non-infringement. In no event shall EMC or its suppliers be liable for

any damages whatsoever including direct, indirect, incidental,

consequential, loss of business profits or special damages, even if EMC or

its suppliers have been advised of the possibility of such damages. Some

states do not allow the exclusion or limitation of liability for

consequential or incidental damages so the foregoing limitation may not

apply.

EMC Product Security Response Center

Security_Alert (at) EMC (dot) com [email concealed]

http://www.emc.com/contact-us/contact/product-security-response-center.h
tm

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