CVE-2021-38505

MEDIUM

Firefox < 94.0 and Firefox ESR < 91.3.0 - Sensitive Data Exposure via Cloud Clipboard

Title source: llm
STIX 2.1

Description

Microsoft introduced a new feature in Windows 10 known as Cloud Clipboard which, if enabled, will record data copied to the clipboard to the cloud, and make it available on other computers in certain scenarios. Applications that wish to prevent copied data from being recorded in Cloud History must use specific clipboard formats; and Firefox before versions 94 and ESR 91.3 did not implement them. This could have caused sensitive data to be recorded to a user's Microsoft account. *This bug only affects Firefox for Windows 10+ with Cloud Clipboard enabled. Other operating systems are unaffected.*. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

References (4)

Core 4
Core References
Issue Tracking, Permissions Required, Vendor Advisory x_refsource_misc
https://bugzilla.mozilla.org/show_bug.cgi?id=1730194

Scores

CVSS v3 6.5
EPSS 0.0035
EPSS Percentile 57.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Details

CWE
CWE-668
Status published
Products (3)
mozilla/firefox < 94.0
mozilla/firefox_esr < 91.3.0
mozilla/thunderbird < 91.3.0
Published Dec 08, 2021
Tracked Since Feb 18, 2026