{"id":"CVE-2019-11730","url":"https://www.cyber-defence.io/tools/cve/CVE-2019-11730","generatedAt":"2026-10-29T01:00:00.253Z","title":"A vulnerability exists where if a user opens a locally saved HTML file, this file can use file: URIs to access other files in the same directory or sub-directories if the names are known or guessed.","description":"A vulnerability exists where if a user opens a locally saved HTML file, this file can use file: URIs to access other files in the same directory or sub-directories if the names are known or guessed. The Fetch API can then be used to read the contents of any files stored in these directories and they may uploaded to a server. It was demonstrated that in combination with a popular Android messaging app, if a malicious HTML attachment is sent to a user and they opened that attachment in Firefox, due to that app's predictable pattern for locally-saved file names, it is possible to read attachments the victim received from other correspondents. This vulnerability affects Firefox ESR < 60.8, Firefox < 68, and Thunderbird < 60.8.","published":"2019-07-23T14:15:17.000Z","lastModified":"2026-06-17T02:13:31.000Z","status":"Modified","sourceIdentifier":"security@mozilla.org","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N"},"cwe":[],"affected":["mozilla/firefox","mozilla/firefox esr","mozilla/thunderbird","debian/debian linux","opensuse/leap","suse/package hub"],"epss":{"score":0.20271,"percentile":0.97457,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"EPSS puts the probability of exploitation in the next 30 days at 20.3%, higher than 97% of all known CVEs. Patch or mitigate before the next change window."},"changes":[],"references":[{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00055.html","tags":["Mailing List","Third Party Advisory"],"source":"security@mozilla.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00058.html","tags":["Mailing List","Third Party Advisory"],"source":"security@mozilla.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00073.html","tags":["Mailing List","Third Party Advisory"],"source":"security@mozilla.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00009.html","tags":["Mailing List","Third Party Advisory"],"source":"security@mozilla.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00010.html","tags":["Mailing List","Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1558299","tags":["Issue Tracking","Permissions Required"],"source":"security@mozilla.org"},{"url":"https://lists.debian.org/debian-lts-announce/2019/08/msg00001.html","tags":["Mailing List","Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://lists.debian.org/debian-lts-announce/2019/08/msg00002.html","tags":["Mailing List","Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://security.gentoo.org/glsa/201908-12","tags":["Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://security.gentoo.org/glsa/201908-20","tags":["Third Party Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2019-21/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2019-22/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2019-23/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00055.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00058.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00073.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00009.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00010.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1558299","tags":["Issue Tracking","Permissions Required"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2019/08/msg00001.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2019/08/msg00002.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/201908-12","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/201908-20","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.mozilla.org/security/advisories/mfsa2019-21/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.mozilla.org/security/advisories/mfsa2019-22/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.mozilla.org/security/advisories/mfsa2019-23/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2019-11730","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."}