NetScaler - Information Disclosure (CVE-2023-4966)

CVE-2023-4966 is a critical vulnerability in NetScaler ADC and NetScaler Gateway, which can lead to sensitive information disclosure when the system is configured as a gateway or virtual server.

CrowdSec has been tracking this vulnerability and its exploits since 10th of March 2025.

According to CrowdSec data, while opportunistic exploitation dominates, a portion of threat actors trying to exploit CVE-2023-4966 apply basic targeting methods such as port or service detection. This indicates emerging patterns of selective targeting. Additionally, according to week-over-week analysis by CrowdSec, exploitation of CVE-2023-4966 is surging. Attack volumes are spiking well above historical norms, indicating widespread and escalating interest from threat actors. CVE-2023-4966 is currently experiencing high visibility and active exploitation across the internet.

Observed exploitation attempts target URLs containing /oauth/idp/.well-known/openid-configuration.