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Vulnerability · Published Dec 8, 2021 · Assigned by mozilla

CVE-2021-38505

Medium 6.5

In plain English

A medium-severity security flaw in Firefox from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 65% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)6.5Medium
Exploit odds (30 days)1.1%top 34.6% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20firefox94.0-r0ALPINE-CVE-2021-38505
Alpine:v3.21firefox94.0-r0ALPINE-CVE-2021-38505
Alpine:v3.22firefox94.0-r0ALPINE-CVE-2021-38505
Alpine:v3.23firefox94.0-r0ALPINE-CVE-2021-38505
Alpine:v3.20firefox-esr91.3.0-r0ALPINE-CVE-2021-38505
Alpine:v3.21firefox-esr91.3.0-r0ALPINE-CVE-2021-38505
Alpine:v3.22firefox-esr91.3.0-r0ALPINE-CVE-2021-38505
Alpine:v3.23firefox-esr91.3.0-r0ALPINE-CVE-2021-38505
Alpine:v3.21librewolf94.0-r0ALPINE-CVE-2021-38505
Alpine:v3.22librewolf94.0-r0ALPINE-CVE-2021-38505
Alpine:v3.23librewolf94.0-r0ALPINE-CVE-2021-38505
Alpine:v3.24librewolf94.0-r0ALPINE-CVE-2021-38505
Alpine:v3.20thunderbird91.3.2-r0ALPINE-CVE-2021-38505
Alpine:v3.21thunderbird91.3.2-r0ALPINE-CVE-2021-38505
Alpine:v3.22thunderbird91.3.2-r0ALPINE-CVE-2021-38505
Alpine:v3.23thunderbird91.3.2-r0ALPINE-CVE-2021-38505
Ubuntu:22.04:LTSmozjs78no fix listedUBUNTU-CVE-2021-38505

Affected products (as reported)

VendorProductVersions
Mozilla Firefox unspecified – before 94
Mozilla Thunderbird unspecified – before 91.3
Mozilla Firefox ESR unspecified – before 91.3

References