Actively exploited · Published Oct 10, 2023 · Assigned by Citrix
CVE-2023-4966Unauthenticated sensitive information disclosure
Critical 9.4 Exploited Ransomware
In plain English
A critical-severity memory corruption in NetScaler ADC from Citrix. Attackers are actively exploiting it in the wild (listed by CISA on October 18, 2023). It has been used in ransomware campaigns. The chance it is exploited in the next 30 days is estimated at 100.0% (higher than 99.9% of all known vulnerabilities). Ready-made attack tooling exists: Metasploit, Nuclei, public proof-of-concept code. 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.
CISA guidance
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.
Federal agencies must remediate by Nov 8, 2023.
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Citrix | NetScaler ADC | 14.1 – before 8.5013.1 – before 49.1513.0 – before 92.1913.1-FIPS – before 37.16412.1-FIPS – before 55.30012.1-NDcPP – before 55.300 |
| Citrix | NetScaler Gateway | 14.1 – before 8.5013.1 – before 49.1513.0 – before 92.19 |
Weakness: CWE-119 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L