{"id":"CVE-2023-4966","url":"https://www.cyber-defence.io/tools/cve/CVE-2023-4966","generatedAt":"2026-10-31T10:23:42.171Z","title":"Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability","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.","published":"2023-10-10T14:15:11.000Z","lastModified":"2026-07-31T04:16:44.000Z","status":"Analyzed","sourceIdentifier":"secure@citrix.com","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"cwe":["CWE-119"],"affected":["citrix/netscaler application delivery controller","citrix/netscaler gateway"],"epss":{"score":0.99999,"percentile":0.99997,"date":"2026-10-30","history":[]},"kev":{"listed":true,"dateAdded":"2023-10-18","dueDate":"2023-11-08","knownRansomwareCampaignUse":"Known","notes":"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.\nhttps://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/, https://support.citrix.com/article/CTX579459/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20234966-and-cve20234967 ;  https://nvd.nist.gov/vuln/detail/CVE-2023-4966"},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"Known to be exploited in the wild (CISA KEV, CISA remediation deadline 8 November 2023). Treat as an emergency change: patch or isolate now, then hunt for prior compromise."},"changes":[],"references":[{"url":"http://packetstormsecurity.com/files/175323/Citrix-Bleed-Session-Token-Leakage-Proof-Of-Concept.html","tags":["Third Party Advisory","VDB Entry"],"source":"secure@citrix.com"},{"url":"https://support.citrix.com/article/CTX579459","tags":["Vendor Advisory"],"source":"secure@citrix.com"},{"url":"http://packetstormsecurity.com/files/175323/Citrix-Bleed-Session-Token-Leakage-Proof-Of-Concept.html","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.citrix.com/article/CTX579459","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-4966","tags":["US Government Resource"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2023-4966","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}