{"id":"CVE-2021-22919","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-22919","generatedAt":"2026-10-27T22:33:05.479Z","title":"A vulnerability has been discovered in Citrix ADC (formerly known as NetScaler ADC) and Citrix Gateway (formerly known as NetScaler Gateway), and Citrix SD-WAN WANOP Edition models 4000-WO, 4100-WO, 5000-WO, and 5100-WO.","description":"A vulnerability has been discovered in Citrix ADC (formerly known as NetScaler ADC) and Citrix Gateway (formerly known as NetScaler Gateway), and Citrix SD-WAN WANOP Edition models 4000-WO, 4100-WO, 5000-WO, and 5100-WO. These vulnerabilities, if exploited, could lead to the limited available disk space on the appliances being fully consumed.","published":"2021-08-05T21:15:11.000Z","lastModified":"2026-06-17T03:38:01.000Z","status":"Modified","sourceIdentifier":"support@hackerone.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:N/I:N/A:H"},"cwe":["CWE-770"],"affected":["citrix/application delivery controller firmware","citrix/gateway","citrix/netscaler gateway","citrix/sd-wan wanop"],"epss":{"score":0.0094,"percentile":0.60694,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.94%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://support.citrix.com/article/CTX319135","tags":["Vendor Advisory"],"source":"support@hackerone.com"},{"url":"https://support.citrix.com/article/CTX319135","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-22919","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."}