CVE-2020-35112
CVE-2020-35112 is a high-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: High (CVSS 3.x base score 8.8)
- CVSS v2: 6.8
- EPSS exploit prediction: 1% (67th percentile)
- Actively exploited: Not listed in CISA KEV
- Affected product: Mozilla Firefox
- Published:
- Last modified:
Description
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.
Frequently asked questions
- What is CVE-2020-35112?
- 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.
- How severe is CVE-2020-35112?
- CVE-2020-35112 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2020-35112 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2020-35112?
- CVE-2020-35112 primarily affects Mozilla Firefox. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2020-35112?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2020-35112 published?
- CVE-2020-35112 was published on 2021-01-07 and last updated on 2026-06-17.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1661365
- https://www.mozilla.org/security/advisories/mfsa2020-54/
- https://www.mozilla.org/security/advisories/mfsa2020-55/
- https://www.mozilla.org/security/advisories/mfsa2020-56/
Affected products (3)
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
- cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
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