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  • Insights

NetScaler ADC and NetScaler Gateway Security Bulletin for CVE-2023-4966 (Citrix Bleed)

Jeff Silverman

2 min read

All Insights

NetScaler ADC and NetScaler Gateway Security Bulletin for CVE-2023-4966 (Citrix Bleed)

Issue

Additional action is recommended to address CVE-2023-4966, which is being called Citrix Bleed.

Timeline

October 10, 2023 – Citrix posted a security bulletin regarding CVE-2023-4966 and CVE-2023-4967 affecting NetScaler ADC and NetScaler Gateway.

October 17, 2023 – Citrix updated the bulletin to indicate that exploits of CVE-2023-4966 on unmitigated appliances have been observed.

October 18, 2023 – CISA added an entry for CVE-2023-4966 to it’s Known Exploited Vulnerabilities (KEV) catalog.

October 23, 2023 – Citrix released a blog post that included a link to guidance from Mandiant regarding remediating CVE-2023-4966

Affected Versions:

The following supported versions of NetScaler ADC and NetScaler Gateway are affected by the vulnerabilities:

  • NetScaler ADC and NetScaler Gateway 14.1 before 14.1-8.50
  • NetScaler ADC and NetScaler Gateway 13.1 before 13.1-49.15
  • NetScaler ADC and NetScaler Gateway 13.0 before 13.0-92.19
  • NetScaler ADC 13.1-FIPS before 13.1-37.164
  • NetScaler ADC 12.1-FIPS before 12.1-55.300
  • NetScaler ADC 12.1-NDcPP before 12.1-55.300

Note: NetScaler ADC and NetScaler Gateway version 12.1 is now End-of-Life (EOL) and is vulnerable.

This bulletin only applies to customer-managed NetScaler ADC and NetScaler Gateway products. Customers using Citrix-managed cloud services or Citrix-managed Adaptive Authentication do not need to take any action.

Recommended Action

Cloud Software Group strongly urges affected customers of NetScaler ADC and NetScaler Gateway to install the relevant updated versions of NetScaler ADC and NetScaler Gateway as soon as possible:

  • NetScaler ADC and NetScaler Gateway 14.1-8.50  and later releases
  • NetScaler ADC and NetScaler Gateway 13.1-49.15  and later releases of 13.1
  • NetScaler ADC and NetScaler Gateway 13.0-92.19 and later releases of 13.0
  • NetScaler ADC 13.1-FIPS 13.1-37.164 and later releases of 13.1-FIPS
  • NetScaler ADC 12.1-FIPS 12.1-55.300 and later releases of 12.1-FIPS
  • NetScaler ADC 12.1-NDcPP 12.1-55.300 and later releases of 12.1-NDcPP

Note: NetScaler ADC and NetScaler Gateway version 12.1 is now End-of-Life (EOL). Customers are recommended to upgrade their appliances to one of the supported versions that address the vulnerabilities.

After installing an updated version, kill all active and persistent sessions using the following commands:

kill icaconnection -all

kill rdp connection -all

kill pcoipConnection -all

kill aaa session -all

clear lb persistentSessions

More information

https://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/

For assistance from the Kraft Kennedy team, please contact us.