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             AUSCERT External Security Bulletin Redistribution

                               ESB-2018.0594
    Authentication Bypass Vulnerability in Citrix NetScaler Application
              Delivery Controller (ADC) and NetScaler Gateway
                               1 March 2018

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        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           Citrix NetScaler Application Delivery Controller
                   Citrix NetScaler Gateway
Publisher:         Citrix
Operating System:  Network Appliance
                   Virtualisation
Impact/Access:     Execute Arbitrary Code/Commands -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2018-5314  

Original Bulletin: 
   https://support.citrix.com/article/CTX232199

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CTX232199

Authentication Bypass Vulnerability in Citrix NetScaler Application Delivery
Controller (ADC) and NetScaler Gateway

Security Bulletin | Medium | Created: 28 Feb 2018 | Modified: 28 Feb 2018

Applicable Products

  o NetScaler 12.0
  o NetScaler 11.1
  o NetScaler 11.0
  o NetScaler Gateway 12.0
  o NetScaler Gateway 11.1
  o NetScaler Gateway 11.0

Description of Problem

A vulnerability has been identified in the management interface of Citrix
NetScaler Application Delivery Controller (ADC) and NetScaler Gateway that, if
exploited, could allow an unauthenticated attacker with access to the NetScaler
management interface to bypass authentication controls and execute arbitrary,
read only commands on the NetScaler appliance.

This vulnerability has been assigned the following CVE number:

  o CVE-2018-5314: Authentication Bypass Vulnerability in Citrix NetScaler ADC
    and NetScaler Gateway Management Interface

This vulnerability affects the following product versions:

  o Citrix NetScaler ADC and NetScaler Gateway version 12.0 builds 41.16,
    41.22, 41.24, 51.24 & 53.6
  o Citrix NetScaler ADC and NetScaler Gateway version 11.1 builds 51.21,
    51.26, 52.13, 53.11, 54.14, 54.16 & 55.10
  o Citrix NetScaler ADC and NetScaler Gateway version 11.0 build 70.12 

This vulnerability also affects the NetScaler Load Balancing instance
distributed with Citrix NetScaler SD-WAN/CloudBridge 4000, 4100, 5000 and 5100
WAN Optimization Edition version 9.3.0

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Mitigating Factors

In order to exploit this vulnerability, an attacker would require access to the
management interface of the NetScaler. In situations where customers have
deployed their NetScaler ADC and NetScaler Gateway appliances in line with
industry best practice, network access to this interface should already be
restricted.

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What Customers Should Do

This vulnerability has been addressed in the following versions of Citrix
NetScaler ADC and NetScaler Gateway:

  o Citrix NetScaler ADC and NetScaler Gateway version 12.0 build 53.13 and
    later
  o Citrix NetScaler ADC and NetScaler Gateway version 11.1 build 55.13 and
    later
  o Citrix NetScaler ADC and NetScaler Gateway version 11.0 build 70.16 and
    later
  o Citrix NetScaler SD-WAN/CloudBridge 4000, 4100, 5000 and 5100 WAN
    Optimization Edition version 9.3.1 and later

Citrix recommends that customers impacted by this vulnerability upgrade to a
version of the Citrix NetScaler ADC, NetScaler Gateway and NetScaler SD-WAN/
Cloudbridge that contains a fix for this issue as soon as possible.

These versions are available on the Citrix website at the following addresses:

https://www.citrix.com/downloads/netscaler-adc/

https://www.citrix.com/downloads/netscaler-gateway/

https://www.citrix.com/downloads/netscaler-sd-wan/

In line with industry best practice, Citrix also recommends that customers
limit access to the management interface to trusted traffic only. Citrix has
published additional guidance on the secure configuration of NetScaler
management interfaces. This can be found at the following location:

https://support.citrix.com/article/CTX228148

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Acknowledgements

Citrix thanks xcuter, blankcon, nullbr4in, loupos, koredge of NAVER BUSINESS
PLATFORM - IT Security (https://www.nbp-corp.com) for working with us to
protect Citrix customers

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What Citrix Is Doing

Citrix is notifying customers and channel partners about this potential
security issue. This article is also available from the Citrix Knowledge Center
at  http://support.citrix.com/.

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Obtaining Support on This Issue

If you require technical assistance with this issue, please contact Citrix
Technical Support. Contact details for Citrix Technical Support are available
at  https://www.citrix.com/support/open-a-support-case.html. 

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Reporting Security Vulnerabilities

Citrix welcomes input regarding the security of its products and considers any
and all potential vulnerabilities seriously. For guidance on how to report
security-related issues to Citrix, please see the following document: CTX081743
- - Reporting Security Issues to Citrix

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Changelog

+--------------------------------------+--------------------------------------+
|Date                                  |Change                                |
+--------------------------------------+--------------------------------------+
|28th February 2018                    |Initial publishing                    |
+--------------------------------------+--------------------------------------+

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