{"cve":"CVE-2017-7821","nvd":{"published":"2018-06-11T21:29:10.920","modified":"2026-06-17T01:25:16.903","status":"Modified","description":"A vulnerability where WebExtensions can download and attempt to open a file of some non-executable file types. This can be triggered without specific user interaction for the file download and open actions. This could be used to trigger known vulnerabilities in the programs that handle those document types. This vulnerability affects Firefox < 56.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-732"],"references":["http://www.securityfocus.com/bid/101057","http://www.securitytracker.com/id/1039465","https://bugzilla.mozilla.org/show_bug.cgi?id=1346515","https://www.mozilla.org/security/advisories/mfsa2017-21/","http://www.securityfocus.com/bid/101057"],"products":["mozilla:firefox"],"source":"nvd","synced_at":"2026-10-19T20:51:47.459859389+00:00"},"epss":{"cve":"CVE-2017-7821","score":0.01911,"percentile":0.79806,"date":"2026-10-31"},"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."]}