CVE-2019-9804

Severity: critical (CVSS 9.8 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2019-04-26 · updated 2026-06-17
Weakness: CWE-78

Description

In Firefox Developer Tools it is possible that pasting the result of the 'Copy as cURL' command into a command shell on macOS will cause the execution of unintended additional bash script commands if the URL was maliciously crafted. This is the result of an issue with the native version of Bash on macOS. *Note: This issue only affects macOS. Other operating systems are unaffected.*. 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=1518026
https://www.mozilla.org/security/advisories/mfsa2019-07/
https://bugzilla.mozilla.org/show_bug.cgi?id=1518026
https://www.mozilla.org/security/advisories/mfsa2019-07/

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