CVE-2019-9807 — 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

Back Back to CVE browser

MEDIUM

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

Published Apr 26, 2019

4.3

MEDIUM

CVSS 3.0

EPSS 0.79%

Description

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.

Affected products

Vendor Mozilla Product Firefox Default
n/a
- Version
  unspecified
  Status
  affected
  Constraints
  <66

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor

Product

Default status

Versions

Mozilla

Firefox

n/a

Version	Status	Constraints
unspecified	affected	<66

Remediation

No remediation recorded yet.

Metrics

0.79% 0.00787

Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.

EPSS probability 0.00787

Score over time

2021–2026

EPSS v1
EPSS v5
EPSS v2
EPSS v3

Percentile over time

EPSS v1
EPSS v5
EPSS v2
EPSS v3

Table of values (11 key points)

Flat stretches are collapsed; showing up to 120 newest points.

Date	Score	Percentile	Model
Oct 1, 2026	0.79% (0.00787)	54.54th	v5 (v2026.06.15)
Sep 20, 2026	0.79% (0.00791)	54.74th	v5 (v2026.06.15)
Jul 20, 2024	0.11% (0.00111)	44.81th	v3 (v2023.03.01)
Jun 20, 2024	0.11% (0.00111)	44.58th	v3 (v2023.03.01)
Mar 7, 2023	0.11% (0.00111)	42.58th	v3 (v2023.03.01)
Mar 6, 2023	0.89% (0.00885)	27.89th	v2 (v2022.01.01)
Apr 1, 2022	0.89% (0.00885)	24.24th	v2 (v2022.01.01)
Mar 31, 2022	2.56% (0.02561)	62.63th	v2 (v2022.01.01)
Jan 6, 2022	2.74% (0.02742)	62.72th	v1
Jan 5, 2022	0.62% (0.00624)	46.35th	v5 (v2026.06.15)
Apr 14, 2021	0.62% (0.00624)	0.00th	v1

Weaknesses (1)

CWE-20

Improper Input Validation

References (2)

https://bugzilla.mozilla.org/show_bug.cgi?id=1362050
x_refsource_MISCExploitIssue TrackingVendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-07/
x_refsource_MISCVendor Advisory

Link	Providers	Tags
https://bugzilla.mozilla.org/show_bug.cgi?id=1362050		x_refsource_MISCExploitIssue TrackingVendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-07/		x_refsource_MISCVendor Advisory