CVE-2020-6799
Command line arguments could have been injected during Firefox invocation as a shell handler for certain unsupported file types.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.53%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 1.53% probability · 75th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-88
- Affected
- mozilla/firefox · mozilla/firefox esr
- Source
- security@mozilla.org
EPSS 1.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.