CVE-2019-9807

Severity: medium (CVSS 4.3 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2019-04-26 · updated 2026-06-17
Weakness: CWE-20

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

Mozilla Firefox: before 66.0 — fixed in 66.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 66.0. Check the vendor advisory for mitigations.

References

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

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