{"cve":"CVE-2020-13998","nvd":{"published":"2020-06-11T02:15:10.713","modified":"2026-06-17T02:54:04.447","status":"Modified","description":"Citrix XenApp 6.5, when 2FA is enabled, allows a remote unauthenticated attacker to ascertain whether a user exists on the server, because the 2FA error page only occurs after a valid username is entered. NOTE: This vulnerability only affects products that are no longer supported by the maintainer","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","score":5.3},"cwes":["CWE-203","CWE-639"],"references":["https://gist.github.com/kampji/11e259d68ad98a6f0f898132f1961a96","https://gist.github.com/kampji/11e259d68ad98a6f0f898132f1961a96"],"products":["citrix:xenapp"],"source":"nvd","synced_at":"2026-10-19T21:05:42.039641217+00:00"},"epss":{"cve":"CVE-2020-13998","score":0.01424,"percentile":0.72906,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}