CVE-2023-4966
Citrix NetScaler ADC, Citrix NetScaler Gateway
Published 10 Oct 2023 · updated 31 Jul 2026 · Analyzed
Exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on 18 Oct 2023, with a remediation deadline of 8 Nov 2023 for US federal agencies. It has been used in ransomware campaigns.
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.
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.
References
- packetstormsecurity.com/files/175323/Citrix-Bleed-Session-Token-Leakage-Proof-Of-Concept.html · Third Party Advisory, VDB Entry
- support.citrix.com/article/CTX579459 · Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-4966 · US Government Resource