CVE-2020-6799

Name: CVE-2020-6799
Creator: NVD / NIST
Published: 2020-03-02T05:15:13.59+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 1.49%

Last modified Jun 17, 2026

CVE-2020-6799 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. Command line arguments could have been injected during Firefox invocation as a shell handler for certain unsupported file types. This required Firefox to be configured as the default handler for a given file type and for a file downloaded to be opened in a third party application that insufficiently sanitized URL data. EPSS estimates a 1.49% chance of exploitation in the next 30 days.

Description

Command line arguments could have been injected during Firefox invocation as a shell handler for certain unsupported file types. This required Firefox to be configured as the default handler for a given file type and for a file downloaded to be opened in a third party application that insufficiently sanitized URL data. In that situation, clicking a link in the third party application could have been used to retrieve and execute files whose location was supplied through command line arguments. Note: This issue only affects Windows operating systems and when Firefox is configured as the default handler for non-default filetypes. Other operating systems are unaffected. This vulnerability affects Firefox < 73 and Firefox < ESR68.5.

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

1.49%

70.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-88

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 73.0
Mozilla	Firefox Esr	< 68.5.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1606596Issue Tracking, Patch, Vendor Advisory
https://security.gentoo.org/glsa/202003-02Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-05/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-06/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1606596Issue Tracking, Patch, Vendor Advisory
https://security.gentoo.org/glsa/202003-02Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-05/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-06/Vendor Advisory

Timeline

Published: Mar 2, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-6799?

How severe is CVE-2020-6799?

CVE-2020-6799 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.49% probability of exploitation in the next 30 days.

How do I fix CVE-2020-6799?

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-2020-6799?

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

Scan your code now

Source: NVD / NIST