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TI-2020-17830 Aliases CVE-2020-35112GHSA-c2mj-qmxh-xhgx

If a user downloaded a file lacking an extension on Windows, and then "Open"-ed it from…

Priority MEDIUM 41Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

If a user downloaded a file lacking an extension on Windows, and then "Open"-ed it from the downloads panel, if there was an executable file in the downloads directory with the same name but with an executable extension (such as .bat or .exe) that executable would have been launched instead. *Note: This issue only affected Windows operating systems. Other operating systems are unaffected.*. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

Why it matters now

EPSS 0.01274 70th percentileScored 2026-11-07
Fix Fixed Firefox (Mozilla): 84Thunderbird (Mozilla): 78.6+1 more product

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaFirefoxbefore 8484Patch availableCNA
MozillaThunderbirdbefore 78.678.6Patch availableCNA
MozillaFirefox ESRbefore 78.678.6Patch availableCNA
  • Firefox VendorMozilla Affected before 84 Fixed in 84 Patch available CNA
  • Thunderbird VendorMozilla Affected before 78.6 Fixed in 78.6 Patch available CNA
  • Firefox ESR VendorMozilla Affected before 78.6 Fixed in 78.6 Patch available CNA

CPE configurations NVD · 4

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*before 84.0VulnerableMozilla
cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*before 78.6.0VulnerableMozilla
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*before 78.6.0VulnerableMozilla
cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*not specified by NVDRunning onMicrosoft
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 84.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* Versions before 78.6.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 78.6.0 Vulnerable ·Mozilla
  • cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Microsoft

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 84
  • Fix · CNA Thunderbird (Mozilla) Fixed in 78.6
  • Fix · CNA Firefox ESR (Mozilla) Fixed in 78.6

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Mozilla Firefox 84

    13 records Highest priority Priority MEDIUM 7 MEDIUM, 6 LOW

    Other records, highest priority first

    • TI-2020-16395 Use after free in Mozilla FirefoxPriority MEDIUM 45
    • TI-2020-16394 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 42
    • TI-2020-17831 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 41
    Show all 13 records →
  • Release ·

    Mozilla Firefox ESR, Thunderbird 78.6

    7 records Highest priority Priority MEDIUM 5 MEDIUM, 2 LOW

    Other records, highest priority first

    • TI-2020-16394 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 42
    • TI-2020-17831 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 41
    • TI-2020-16397 Out-of-bounds write in Mozilla FirefoxPriority MEDIUM 41
    Show all 7 records →

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

Not affected: 4 products
  • Red Hat Enterprise Linux 5
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2020-35112
  2. 2026-10-03 Alias added: GHSA-c2mj-qmxh-xhgx

References

Advisory 3

Other 1

  • TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
  • TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
  • TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
  • TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
  • TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
  • TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
See all 3444 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences