Buffer overflow in Citrix Netscaler ADC and Citrix NetScaler Gateway - CVE-2023-4966
Published: October 11, 2023 / Updated: February 25, 2025
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error. A remote non-authenticated attacker can send specially crafted data to the device, trigger memory corruption and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system but requires that the appliance is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or as AAAvirtualserver.
Note, the vulnerability is being actively exploited in the wild since August 2023.
Affected software
Citrix NetScaler Gateway
How to mitigate CVE-2023-4966
Install updates from vendor's website.
For FIPS releases install the following versions:
- NetScaler ADC 13.1-FIPS version 13.1-37.164
- NetScaler ADC 12.1-FIPS version 12.1-55.300
- NetScaler ADC 12.1-NDcPP version 12.1-55.300
Citrix NetScaler Gateway - addressed in versions 13.0-92.19, 13.1-49.15, 14.1-8.50
Links to Public Exploits and PoC-codes
- Exploit #11171 - CVE-2023-4966 (An Exploitation script developed to exploit the CVE-2023-4966 bleed citrix information disclosure vulnerability) (February 25, 2025)
- Exploit #10114 - citrix_cve-2023-4966 (Citrix CVE-2023-4966 from assetnote modified for parallel and file handling) (June 21, 2024)
- Exploit #9618 - CVE-2023-4966 (An Exploitation script developed to exploit the CVE-2023-4966 bleed citrix information disclosure vulnerability) (March 22, 2024)
- Exploit #9399 - citrix CVE-2023-4966 (November 2, 2023)
- Exploit #9396 - Citrix ADC (NetScaler) Bleed Scanner (October 30, 2023)
- Exploit #9392 - exploits (Repository to store exploits created by Assetnotes Security Research team) (October 25, 2023)