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Fencer Intel
medium 4.3

CVE-2019-9807 json

When arbitrary text is sent over an FTP connection and a page reload is initiated, it is possible to create a modal alert message with this…

published 7y ago modified 4mo ago also EUVD-2019-19169

cvss
4.3
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 56%
public exploits
0
none known

Summary

When arbitrary text is sent over an FTP connection and a page reload is initiated, it is possible to create a modal alert message with this text as the content. This could potentially be used for social engineering attacks. This vulnerability affects Firefox < 66.

Patch / fix

  • Mozilla Firefox 66
  • firefox Ubuntu 14.04 LTS 66.0.1+build1-0ubuntu0.14.04.1
  • firefox Ubuntu 16.04 LTS 66.0+build3-0ubuntu0.16.04.2
  • firefox Ubuntu 18.04 LTS 66.0+build3-0ubuntu0.18.04.1

ubuntu advisories UBUNTU-CVE-2019-9807

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 92.0-1.2

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10600-1

  • firefox Arch Linux 66.0-1

arch linux advisories AVG-925

Is CVE-2019-9807 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Exploit prediction

0.79% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • bugzilla.mozilla.org https://bugzilla.mozilla.org/show_bug.cgi?id=1362050 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 4.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

Affected products

  • Mozilla Firefox

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.