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Vulnerability details: VCID-61rr-tpyu-6ket
Vulnerability ID VCID-61rr-tpyu-6ket
Aliases CVE-2021-38505
Summary 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.*
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (2)
CWE-838 Inappropriate Encoding for Output Context
CWE-668 Exposure of Resource to Wrong Sphere
System Score Found at
cvssv3 7.5 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-38505.json
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
epss 0.00444 https://api.first.org/data/v1/epss?cve=CVE-2021-38505
cvssv3.1 7.5 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv2 4.3 https://nvd.nist.gov/vuln/detail/CVE-2021-38505
cvssv3.1 6.5 https://nvd.nist.gov/vuln/detail/CVE-2021-38505
archlinux High https://security.archlinux.org/AVG-2512
archlinux High https://security.archlinux.org/AVG-2519
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-48
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-49
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-50
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-38505.json
https://api.first.org/data/v1/epss?cve=CVE-2021-38505
https://bugzilla.mozilla.org/show_bug.cgi?id=1730194
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://www.mozilla.org/security/advisories/mfsa2021-48/
https://www.mozilla.org/security/advisories/mfsa2021-49/
https://www.mozilla.org/security/advisories/mfsa2021-50/
2019623 https://bugzilla.redhat.com/show_bug.cgi?id=2019623
AVG-2512 https://security.archlinux.org/AVG-2512
AVG-2519 https://security.archlinux.org/AVG-2519
CVE-2021-38505 https://nvd.nist.gov/vuln/detail/CVE-2021-38505
mfsa2021-48 https://www.mozilla.org/en-US/security/advisories/mfsa2021-48
mfsa2021-49 https://www.mozilla.org/en-US/security/advisories/mfsa2021-49
mfsa2021-50 https://www.mozilla.org/en-US/security/advisories/mfsa2021-50
No exploits are available.
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-38505.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: AV:N/AC:M/Au:N/C:P/I:N/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-38505
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-38505
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.62449
EPSS Score 0.00444
Published At July 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:09:46.309706+00:00 Mozilla Importer Import https://github.com/mozilla/foundation-security-advisories/blob/master/announce/2021/mfsa2021-49.yml 37.0.0