Vulmon
Description of Problem
A flaw has been identified in the AppFirewall feature of Citrix NetScaler Application Delivery Controller (ADC) and Citrix NetScaler Gateway that could result in arbitrary code execution and host compromise.
The following vulnerability has been addressed:
CVE-2018-7218 (Critical): Vulnerability in Citrix NetScaler Application Delivery Controller and NetScaler Gateway leading to arbitrary code execution and host compromise
The vulnerability affects the following versions of Citrix NetScaler ADC and NetScaler Gateway:
- Version 12.0 up to and including 12.0 Build 56.20
- Version 11.1 up to and including 11.1 Build 57.11/57.13
- Version 11.0 up to and including 11.0 Build 71.18/71.22
- Version 10.5 up to and including 10.5 Build 67.10/67.13
Mitigating Factors
Only Citrix NetScaler ADC and NetScaler Gateway appliances that have been configured to use the AppFirewall functionality are affected by this vulnerability.
As a temporary workaround, customers using the AppFirewall feature may reconfigure the profile settings to only process HTML traffic –
set appfw profile <profilename> –type HTML
A full explanation of configuration options and steps is available here.
Please note that this may involve potential functionality loss depending on your deployment. Reconfiguring the Citrix NetScaler ADC or NetScaler Gateway appliance according to these instructions will disable any previously configured XML checks.
What Customers Should Do
This vulnerability has been addressed in the following versions of Citrix NetScaler ADC and NetScaler Gateway:
• Citrix NetScaler ADC and NetScaler Gateway version 12.0 Build 57.24 and later
• Citrix NetScaler ADC and NetScaler Gateway version 11.1 Build 58.13 and later
• Citrix NetScaler ADC and NetScaler Gateway version 11.0 Build 71.24 and later
• Citrix NetScaler ADC and NetScaler Gateway version 10.5 Build 68.7 and later
Citrix NetScaler ADC and NetScaler Gateway version 10.1 are not planned to be updated as part of remediating this issue. Customers on version 10.1 should plan to move to a later version to receive the latest security updates.
These new versions can be downloaded from the following locations:
https://www.citrix.com/downloads/netscaler-adc.html
https://www.citrix.com/downloads/netscaler-gateway.html
Citrix strongly recommends that customers using affected versions of NetScaler ADC and NetScaler Gateway to upgrade to a version of the appliance firmware that contains the fixes for this issue as soon as possible.
Acknowledgements
Citrix thanks Mathias Morbitzer and Dennis Titze of Fraunhofer AISEC for working with us to protect Citrix customers.
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/.
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.
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
Changelog
| Date | Change |
| May 14 2018 | Initial Publishing |
| May 16 2018 | Clarified affected version description |