Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability
Citrix · NetScaler ADC and NetScaler Gateway
What it is
Citrix NetScaler ADC and NetScaler Gateway contain a buffer overflow vulnerability that allows for sensitive information disclosure when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.
Why we say that
- Linked by CISA to known ransomware campaigns
- EPSS puts exploitation in the next 30 days at 100%
- CISA's federal remediation deadline (2023-11-08) has passed
- CVSS 9.4 critical
- Listed in the CISA Known Exploited Vulnerabilities catalogue
Every line above comes from a named public source. Where the evidence is thin, we say so rather than inventing confidence — see methodology.
What to do
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.
What it costs when this goes wrong
This is where UK enforcement meets the vulnerability record. This vulnerability is used in ransomware campaigns; here is what ransomware has cost UK organisations at the regulator.
- Advanced Computer Software Group Limited The Information Commissioner’s Office (ICO) has fined Advanced Computer Software Group Ltd (Advanced) £3.07m for security failings…
- Optionis Group Limited The data controller suffered a ransomware attack, which resulted in the exfiltration of personal data. A reprimand was issued in r…