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.

Severity (CVSS 3.1)9.4Critical
Exploit odds (30 days)100.0%top 0.0% of all CVEs
Exploited in the wildYesCISA KEV since Oct 18, 2023
Attack tooling3Metasploit, Nuclei, Public PoC

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)

VendorProductVersions
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

References