{"id":"CVE-2017-7783","url":"https://www.cyber-defence.io/tools/cve/CVE-2017-7783","generatedAt":"2026-10-28T19:47:46.564Z","title":"If a long user name is used in a username/password combination in a site URL (such as \" http://UserName:Password@example.com\"), the resulting modal prompt will hang in a non-responsive state or crash, causing a denial of service.","description":"If a long user name is used in a username/password combination in a site URL (such as \" http://UserName:Password@example.com\"), the resulting modal prompt will hang in a non-responsive state or crash, causing a denial of service. This vulnerability affects Firefox < 55.","published":"2018-06-11T21:29:09.000Z","lastModified":"2026-06-17T01:25:11.000Z","status":"Modified","sourceIdentifier":"security@mozilla.org","cvss":{"version":"3.0","score":7.5,"severity":"HIGH","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-20"],"affected":["mozilla/firefox"],"epss":{"score":0.13846,"percentile":0.96506,"date":"2026-10-27","history":[{"date":"2026-09-21","score":0.10342,"percentile":0.95565},{"date":"2026-09-22","score":0.1412,"percentile":0.96402}]},"kev":{"listed":false},"exploits":{"count":1,"verified":true,"firstPublished":"2017-10-20","source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[{"edbId":43020,"kind":"exploit","title":"Mozilla Firefox < 55 - Denial of Service","url":"https://www.exploit-db.com/exploits/43020","sourceUrl":"https://gitlab.com/exploit-database/exploitdb/-/blob/main/exploits/multiple/dos/43020.txt","file":"exploits/multiple/dos/43020.txt","published":"2017-10-20","added":"2017-10-20","updated":"2017-10-20","author":"Amit Sangra","type":"dos","platform":"multiple","port":null,"verified":true,"codes":["CVE-2017-7783"],"tags":null,"aliases":null,"applicationUrl":null,"screenshotUrl":null,"referenceUrl":null}]},"verdict":{"level":"urgent","text":"EPSS puts the probability of exploitation in the next 30 days at 13.8%, higher than 97% of all known CVEs. Patch or mitigate before the next change window."},"changes":[],"references":[{"url":"http://www.securityfocus.com/bid/100401","tags":["Third Party Advisory","VDB Entry"],"source":"security@mozilla.org"},{"url":"http://www.securitytracker.com/id/1039124","tags":["Third Party Advisory","VDB Entry"],"source":"security@mozilla.org"},{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1360842","tags":["Exploit","Issue Tracking","Patch"],"source":"security@mozilla.org"},{"url":"https://www.exploit-db.com/exploits/43020/","tags":["Third Party Advisory","VDB Entry"],"source":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2017-18/","tags":["Vendor Advisory"],"source":"security@mozilla.org"},{"url":"http://www.securityfocus.com/bid/100401","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securitytracker.com/id/1039124","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1360842","tags":["Exploit","Issue Tracking","Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.exploit-db.com/exploits/43020/","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.mozilla.org/security/advisories/mfsa2017-18/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2017-7783","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."}