What’s Vulnerable › Vulnerabilities

CVE-2020-6799

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-03-02 · updated 2026-06-17
• Weakness: CWE-88

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.

Affected products

• Mozilla Firefox: before 73.0 — fixed in 73.0
• Mozilla Firefox ESR: before 68.5.0 — fixed in 68.5.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 73.0; Mozilla Firefox ESR 68.5.0. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1606596
• https://security.gentoo.org/glsa/202003-02
• https://www.mozilla.org/security/advisories/mfsa2020-05/
• https://www.mozilla.org/security/advisories/mfsa2020-06/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1606596
• https://security.gentoo.org/glsa/202003-02
• https://www.mozilla.org/security/advisories/mfsa2020-05/
• https://www.mozilla.org/security/advisories/mfsa2020-06/

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