Citrix has identified an isolated issue in which some customers experienced a crash condition after upgrading to the current build with HTTP/2 enabled.
What Product is Affected?
NetScaler appliance upgraded to version NS13.1 Build 45.63 or NS13.0 Build 90.11
*No other versions are impacted by this HTTP/2 issue.
Is there a workaround or fix?
Workaround: Disable http2 in the HTTP profile bound to the virtual server.
Fix: Engineering is working on a code fix and will update the ETA of the next build as soon as possible.
How to verify if http2 is enabled?
Run the following command from the CLI and verify if http2Direct Is reported as enabled.
> show run | grep http2
Example of output if enabled:
> set ns httpProfile <name of httpprofile> -http2 ENABLED -http2Direct ENABLED
Example of output if not enabled:
> set ns httpProfile <name of httpprofile> -http2 DISABLED -http2Direct DISABLED
How to disable http2 if enabled?
> set ns httpProfile <name of the httpprofile> -http2 DISABLED -http2Direct DISABLED
Citrix published on May, 9th a new Security Bulletin for NetScaler ADC and Netscaler Gateway. The severity is rated as medium. AXACOM is recommending to upgrade the NetScaler ADCs and Gateways in the next few days according to the Citrix CTX477714.
Please monitor as well the Citrix CTX article under the following link:
Vulnerabilities have been discovered in Citrix ADC and Citrix Gateway listed below, that, if exploited, could result in the following security issues:
Impacted Products, Versions and Components
The following supported versions of Citrix ADC and Citrix Gateway are affected by this vulnerability:
Citrix ADC and Citrix Gateway 13.1 before 13.1-45.61
Citrix ADC and Citrix Gateway 13.0 before 13.0-90.11
Citrix ADC and Citrix Gateway 12.1 before 12.1-65.35
Citrix ADC 12.1-FIPS before 12.1-55.296
Citrix ADC 12.1-NDcPP before 12.1-55.296
This bulletin only applies to customer-managed Citrix ADC and Citrix Gateway. Customers using Citrix-managed cloud services or Citrix-managed Adaptive Authentication do not need to take any action.
CVE ID
Description
Pre-requisites
CWE
CVSS
CVE-2023-24488
Cross site scripting
Appliance must be configured as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server
Affected customers of Citrix ADC and Citrix Gateway are recommended to install the relevant updated versions of Citrix ADC or Citrix Gateway as soon as possible:
Citrix ADC and Citrix Gateway 13.1-45.61 and later releases
Citrix ADC and Citrix Gateway 13.0-90.11 and later releases of 13.0
Citrix ADC and Citrix Gateway 12.1-65.35 and later releases of 12.1
Citrix ADC 12.1-FIPS 12.1-55.296 and later releases of 12.1-FIPS
Citrix ADC 13.1-FIPS 13.1-37.150 and later releases of 13.1-FIPS
Citrix ADC 12.1-NDcPP 12.1-55.296 and later releases of 12.1-NDcPP
