CVE-2023-4966: Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability

CVE-2023-4966 · Severity: critical · CVSS 9.4 · Exploited in the wild · Published 2023-10-18

A buffer overflow vulnerability in Citrix NetScaler ADC and NetScaler Gateway allows for sensitive information disclosure. The flaw is exploitable when the devices are configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.

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

Quick answers

Is CVE-2023-4966 exploited in the wild?
Yes. CVE-2023-4966 is known to be exploited in the wild, first recorded on 18 October 2023. Treat it as urgent.
How severe is CVE-2023-4966?
Critical severity, with a CVSS score of 9.4, published 18 October 2023.
Which products and versions are affected?
Citrix Systems, Inc. NetScaler ADC; Citrix Systems, Inc. NetScaler Gateway.
Is there a fix for CVE-2023-4966?
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-2023-4966 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2023-4966?
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 Systems, Inc. NetScaler ADC
  • Citrix Systems, Inc. NetScaler Gateway

Timeline

  • 2023-10-18: disclosed
  • 2023-10-18: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
  • 2023-10-18: advisory: Vendor advisory CTX579459 published

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