Actively exploited in the wild
Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability
Citrix - NetScaler ADC and NetScaler Gateway · Listed in the CISA KEV since 2023-10-18. This indicates confirmed attacks in production environments.
Required action: Apply mitigations and kill all active and persistent sessions per vendor instructions [https://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/] OR discontinue use of the product if mitigations are unavailable.
CVE-2023-4966
CriticalCVSS 9.4KEVExploitation Probability (EPSS)
Very high risk100th percentile - higher than 100% of all known CVEs
Summary
Sensitive information disclosure vulnerability in NetScaler ADC and NetScaler Gateway when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.
Risk Assessment
An attacker could access confidential data such as passwords or session keys, potentially compromising the entire network security.
Recommendation
Immediately update NetScaler ADC and NetScaler Gateway to the latest version and review the configuration of gateways and AAA servers.
Original NVD description (English source)
Sensitive information disclosure in NetScaler ADC and NetScaler Gateway when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.