All vulnerabilities
CVE-2023-6549

Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability

Citrix NetScaler ADC and NetScaler GatewayNetwork & edge
Open in ThreatlineRecord JSON
CVSS
8.2High
ExploitationExploited in the wildAdded to KEV 17 Jan 2024CISA KEV
Exploit odds (EPSS)57.6%Chance of exploitation activity in the next 30 days, higher than 99% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in12.35Also 51.15, 92.21 and 2 moreCVE List
Federal deadline7 Feb 2024Remediation due date for US federal agenciesCISA KEV
CISA required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. CISA KEV

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

  1. 17 Jan 2024Added to CISA KEVCISA KEV
  2. 17 Jan 2024, 20:15 UTCPublishedCVE List

Public exploit code and templates 1

  • Scanner templateCitrix Netscaler ADC & Gateway - Out-Of-Bounds Memory ReadNuclei

Listed so defenders can prioritize. Threatline links to the source and does not host exploit code.

Description

Citrix NetScaler ADC and NetScaler Gateway contain a buffer overflow vulnerability that allows for a denial-of-service when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.

Text from CVE List

Affected versions 6

  • NetScaler ADCaffected: 14.1 before 12.35CVE List
  • NetScaler ADCaffected: 13.1 before 51.15CVE List
  • NetScaler ADCaffected: 13.0 before 92.21CVE List
  • NetScaler ADCaffected: 13.1-FIPS before 37.176CVE List
  • NetScaler ADCaffected: 12.1-FIPS before 55.302CVE List
  • NetScaler ADCaffected: 12.1-NDcPP before 55.302CVE List

References 3