CVE-2017-5419
If a malicious site repeatedly triggers a modal authentication prompt, eventually the browser UI will become non-responsive, requiring shutdown through the operating system.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.23%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
If a malicious site repeatedly triggers a modal authentication prompt, eventually the browser UI will become non-responsive, requiring shutdown through the operating system. This is a denial of service (DOS) attack. This vulnerability affects Firefox < 52 and Thunderbird < 52.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 2.23% probability · 83th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
EPSS 2.2% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.securityfocus.com/bid/96692Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1037966Third Party Advisory, VDB Entry
- https://bugzilla.mozilla.org/show_bug.cgi?id=1312243Exploit, Issue Tracking, Patch
- https://www.mozilla.org/security/advisories/mfsa2017-05/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-09/Vendor Advisory
- http://www.securityfocus.com/bid/96692Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1037966Third Party Advisory, VDB Entry
- https://bugzilla.mozilla.org/show_bug.cgi?id=1312243Exploit, Issue Tracking, Patch
- https://www.mozilla.org/security/advisories/mfsa2017-05/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-09/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.