search menu icon-carat-right cmu-wordmark

CERT Coordination Center

Citrix NetScaler and Access Gateway Enterprise Edition unauthorized access to network resources vulnerability

Vulnerability Note VU#521612

Original Release Date: 2013-04-25 | Last Revised: 2013-04-25

Overview

Citrix NetScaler and Access Gateway Enterprise Edition contain a vulnerability which could result in unauthorized access to network resources.

Description

Citrix NetScaler and Access Gateway Enterprise Edition contain a vulnerability which could allow a remote attacker to gain unauthorized access to network resources.

For additional information please see Citrix Advisory.

Impact

A remote attacker could gain unauthorized access to internal network resources.

Solution

Upgrade

Citrix Advisory states:

A new version of the NetScaler appliance firmware has been released to address this vulnerability. Citrix strongly recommends that affected customers upgrade their appliances to version 9.3.62.x or later as soon as possible. Customers using NetScaler Access Gateway Enterprise Edition in the Common Criteria evaluated configuration should upgrade to 9.3.53.6. These new firmware versions can be downloaded from the Citrix website at the following location: https://www.citrix.com/downloads/netscaler-adc/firmware.html

Customers using NetScaler appliance firmware versions up to and including 10.0.74.4 in a double hop deployment should apply the following configuration change from the NSCLI:

>add ns acl allowedHost ALLOW -srcIP <MIP/SNIP address of AGEE in the first DMZ> -destIP <ICA proxy VIP> -priority 10 #permit traffic only from the AGEE appliance in the first DMZ

>enable ns acl allowedHost

>add ns acl denyAll DENY -srcIP 0.0.0.0 - 255.255.255.255 -destIP <ICA proxy VIP> -priority 20 #block everything else

>enable ns acl denyAll
>apply ns acls

Vendor Information

Citrix Advisory states:

    This vulnerability affects the following NetScaler Access Gateway Enterprise Edition configurations:

    • All appliance firmware versions up to and including version 9.3.61.5 with the exception of Common Criteria build 9.3.53.6.

    • All version 10.0 appliance firmware up to and including version 10.0.74.4 when deployed in a double hop configuration only.
    Customers using an appliance with appliance firmware version 10.0 that is not deployed in a double hop configuration are not affected by this vulnerability.

521612
 

Citrix Affected

Notified:  March 15, 2013 Updated: April 25, 2013

Status

Affected

Vendor Statement

A new version of the NetScaler appliance firmware has been released to address this vulnerability. Citrix strongly recommends that affected customers upgrade their appliances to version 9.3.62.x or later as soon as possible. Customers using NetScaler Access Gateway Enterprise Edition in the Common Criteria evaluated configuration should upgrade to 9.3.53.6. These new firmware versions can be downloaded from the Citrix website at the following location: https://www.citrix.com/downloads/netscaler-adc/firmware.html

Customers using NetScaler appliance firmware versions up to and including 10.0.74.4 in a double hop deployment should apply the following configuration change from the NSCLI:

>add ns acl allowedHost ALLOW -srcIP <MIP/SNIP address of AGEE in the first DMZ> -destIP <ICA proxy VIP> -priority 10 #permit traffic only from the AGEE appliance in the first DMZ

>enable ns acl allowedHost

>add ns acl denyAll DENY -srcIP 0.0.0.0 - 255.255.255.255 -destIP <ICA proxy VIP> -priority 20 #block everything else

>enable ns acl denyAll
>apply ns acls

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Vendor References


CVSS Metrics

Group Score Vector
Base 5.4 AV:N/AC:H/Au:N/C:C/I:N/A:N
Temporal 4.2 E:POC/RL:OF/RC:C
Environmental 4.5 CDP:LM/TD:M/CR:ND/IR:ND/AR:ND

References

Acknowledgements

Thanks to HyeongKwan Lee of SK Planet for reporting this vulnerability.

This document was written by Michael Orlando.

Other Information

CVE IDs: CVE-2013-2767
Date Public: 2013-04-25
Date First Published: 2013-04-25
Date Last Updated: 2013-04-25 13:11 UTC
Document Revision: 15

Sponsored by CISA.