Research · Jun 25, 2025
Critical Buffer Overflow Vulnerability in Citrix NetScaler ADC and Gateway
A newly discovered buffer overflow vulnerability in Citrix NetScaler ADC and Gateway could lead to serious security risks, including Denial of Service.
What changed
Citrix has identified a buffer overflow vulnerability in its NetScaler ADC and Gateway products. This flaw can result in unintended control flow, potentially leading to a Denial of Service (DoS) situation.
The vulnerability arises when NetScaler is configured as a Gateway (including VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or an AAA virtual server.
Who is affected
The vulnerability affects various configurations of Citrix NetScaler, which is widely used in enterprise environments for application delivery and remote access.
Organizations relying on Citrix NetScaler ADC and Gateway for secure application access and VPN services are particularly at risk.
- Citrix NetScaler ADC
- Citrix NetScaler Gateway
- Enterprises utilizing Citrix for application delivery
- Organizations using VPN services through Citrix
What to do
Organizations using affected versions of Citrix NetScaler should assess their configurations and implement necessary security measures to mitigate the risks associated with this vulnerability.
Regularly updating software and monitoring for security patches from Citrix can help protect against potential exploits.