CVE-2023-6549: Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability

CVE-2023-6549 · Severity: critical · CVSS 8.2 · Exploited in the wild · Published 2024-01-17

A buffer overflow vulnerability in Citrix NetScaler ADC and NetScaler Gateway allows an unauthenticated attacker to cause a denial-of-service (DoS) or perform an out-of-bounds memory read. The vulnerability is exploitable when the device is configured as a Gateway or AAA virtual server.

Technologies: Citrix NetScaler ADC, Citrix NetScaler Gateway. Vendors: Citrix.

Quick answers

Is CVE-2023-6549 exploited in the wild?
Yes. CVE-2023-6549 is known to be exploited in the wild, first recorded on 17 January 2024. Treat it as urgent.
How severe is CVE-2023-6549?
Critical severity, with a CVSS score of 8.2, published 17 January 2024.
Which products and versions are affected?
Citrix NetScaler ADC 13.0 before 13.0-92.21, 13.1 before 13.1-51.15, 14.1 before 14.1-12.35, 12.1-FIPS before 12.1-55.302, 13.1-FIPS before 13.1-37.176, 12.1-NDcPP before 12.1-55.302; Citrix NetScaler Gateway 13.0 before 13.0-92.21, 13.1 before 13.1-51.15, 14.1 before 14.1-12.35.
Is there a fix for CVE-2023-6549?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2023-6549 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2023-6549?
Check whether you run Citrix NetScaler ADC or Citrix NetScaler Gateway. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Affected products

  • Citrix NetScaler ADC 13.0 before 13.0-92.21, 13.1 before 13.1-51.15, 14.1 before 14.1-12.35, 12.1-FIPS before 12.1-55.302, 13.1-FIPS before 13.1-37.176, 12.1-NDcPP before 12.1-55.302
  • Citrix NetScaler Gateway 13.0 before 13.0-92.21, 13.1 before 13.1-51.15, 14.1 before 14.1-12.35

Timeline

  • 2024-01-17: disclosed
  • 2024-01-17: kev added: Added to CISA KEV catalog due to active exploitation.
  • 2024-01-17: advisory: Citrix security bulletin CTX584986 published.

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