CVE-2020-12393

Name: CVE-2020-12393
Creator: NVD / NIST
Published: 2020-05-26T17:15:10.167+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 1.01%

Last modified Jun 17, 2026

CVE-2020-12393 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. The 'Copy as cURL' feature of Devtools' network tab did not properly escape the HTTP method of a request, which can be controlled by the website. If a user used the 'Copy as cURL' feature and pasted the command into a terminal, it could have resulted in command injection and arbitrary command execution. EPSS estimates a 1.01% chance of exploitation in the next 30 days.

Description

The 'Copy as cURL' feature of Devtools' network tab did not properly escape the HTTP method of a request, which can be controlled by the website. If a user used the 'Copy as cURL' feature and pasted the command into a terminal, it could have resulted in command injection and arbitrary command execution. *Note: this issue only affects Firefox on Windows operating systems.*. This vulnerability affects Firefox ESR < 68.8, Firefox < 76, and Thunderbird < 68.8.0.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

1.01%

58.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-78

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 76.0
Mozilla	Firefox Esr	< 68.8.0
Mozilla	Thunderbird	< 68.8.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1615471Permissions Required
https://www.mozilla.org/security/advisories/mfsa2020-16/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-17/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-18/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1615471Permissions Required
https://www.mozilla.org/security/advisories/mfsa2020-16/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-17/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-18/Vendor Advisory

Timeline

Published: May 26, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-12393?

How severe is CVE-2020-12393?

CVE-2020-12393 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 1.01% probability of exploitation in the next 30 days.

How do I fix CVE-2020-12393?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-12393?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST