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12 September 2019

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             AUSCERT External Security Bulletin Redistribution

                       Citrix SD-WAN Security Update
                             12 September 2019


        AusCERT Security Bulletin Summary

Product:           Citrix SD-WAN
Publisher:         Citrix
Operating System:  Network Appliance
Impact/Access:     Denial of Service -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2019-11479 CVE-2019-11478 CVE-2019-11477

Reference:         ASB-2019.0174

Original Bulletin: 

- --------------------------BEGIN INCLUDED TEXT--------------------

Citrix SD-WAN Security Update

Reference: CTX256918

Category : Medium

Created  : 11 Sep 2019

Modified : 11 Sep 2019

Applicable Products

  o Citrix SD-WAN

Description of Problem

Multiple denial of service vulnerabilities have been identified in the Citrix
SD-WAN Appliance and Citrix SD-WAN Center Management Console. These
vulnerabilities could permit a remote attacker to cause a denial of service by
causing a host crash or by causing reduced service capacity due to resource
exhaustion. The vulnerabilities have been assigned the following CVE numbers.

  o CVE-2019-11477: SACK Panic
  o CVE-2019-11478: SACK Slowness or Excess Resource Usage
  o CVE-2019-11479: Excess Resource Consumption Due to Low MSS Values

Mitigating Factors

In order to protect against these vulnerabilities and web application related
issues, Citrix recommends access to the management console be restricted. In
situations where customers have deployed their management console in line with
industry best practice, network access to this interface should already be

Security Best Practices:

10.x - https://docs.citrix.com/en-us/netscaler-sd-wan/10/best-practices/

What Customers Should Do

These vulnerabilities have been addressed in the following software versions:

o NetScaler SD-WAN 10.0.8

o Citrix SD-WAN 10.2.4

o Citrix SD-WAN 11.0.1

Citrix recommends that customers using vulnerable software upgrade their
management console to the new version or later as soon as possible.

Customers using versions of the product that will not contain a fix (i.e.
9.3.x) are advised to consider upgrading to a version that does contain the fix
(i.e. 11.0.1)

The new software versions will be available on the Citrix website. Information
on the available versions can be found at the following location:


In line with general best practice, Citrix also recommends that customers limit
access to the management console of the Citrix SD-WAN Appliance and Citrix
SD-WAN Center Management Console to trusted network traffic only.


|Date                                  |Change                                |
|11th September 2019                   |Initial Publication                   |

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