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Vulnerability details: VCID-uhvw-389v-aaaq
Vulnerability ID VCID-uhvw-389v-aaaq
Aliases CVE-2021-38506
Summary Through a series of navigations, Firefox could have entered fullscreen mode without notification or warning to the user. This could lead to spoofing attacks on the browser UI including phishing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (1)
CWE-1021 Improper Restriction of Rendered UI Layers or Frames
System Score Found at
generic_textual Medium http://people.canonical.com/~ubuntu-security/cve/2021/CVE-2021-38506.html
rhas Important https://access.redhat.com/errata/RHSA-2021:4116
rhas Important https://access.redhat.com/errata/RHSA-2021:4123
rhas Important https://access.redhat.com/errata/RHSA-2021:4130
rhas Important https://access.redhat.com/errata/RHSA-2021:4132
rhas Important https://access.redhat.com/errata/RHSA-2021:4133
rhas Important https://access.redhat.com/errata/RHSA-2021:4134
rhas Important https://access.redhat.com/errata/RHSA-2021:4605
rhas Important https://access.redhat.com/errata/RHSA-2021:4607
cvssv3 7.5 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-38506.json
epss 0.00207 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
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epss 0.00207 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
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epss 0.00207 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
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epss 0.00207 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.0022 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00329 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00616 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00616 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00616 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00616 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00623 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00623 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00623 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00623 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00623 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00623 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00623 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00623 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00623 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
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epss 0.00623 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
epss 0.00623 https://api.first.org/data/v1/epss?cve=CVE-2021-38506
rhbs high https://bugzilla.redhat.com/show_bug.cgi?id=2019624
generic_textual Medium https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38496
generic_textual Medium https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38500
generic_textual Medium https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38503
generic_textual Medium https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38504
generic_textual Medium https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38506
generic_textual Medium https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38507
generic_textual Medium https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38508
generic_textual Medium https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38509
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-2021-38506
cvssv3 4.3 https://nvd.nist.gov/vuln/detail/CVE-2021-38506
cvssv3.1 4.3 https://nvd.nist.gov/vuln/detail/CVE-2021-38506
archlinux High https://security.archlinux.org/AVG-2511
archlinux High https://security.archlinux.org/AVG-2518
cvssv3.1 7.5 https://security.gentoo.org/glsa/202208-14
generic_textual HIGH https://security.gentoo.org/glsa/202208-14
generic_textual Medium https://ubuntu.com/security/notices/USN-5131-1
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-48
generic_textual Medium https://www.mozilla.org/en-US/security/advisories/mfsa2021-48/#CVE-2021-38506
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-49
generic_textual Medium https://www.mozilla.org/en-US/security/advisories/mfsa2021-49/#CVE-2021-38506
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-50
Reference id Reference type URL
http://people.canonical.com/~ubuntu-security/cve/2021/CVE-2021-38506.html
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-38506.json
https://api.first.org/data/v1/epss?cve=CVE-2021-38506
https://bugzilla.mozilla.org/show_bug.cgi?id=1730750
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38496
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38500
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38502
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38503
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38504
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38506
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38507
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38508
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-38509
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-4126
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-4129
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43528
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43529
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43534
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43535
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43536
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43537
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43538
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43539
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43541
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43542
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43543
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43545
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-43546
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-44538
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html
https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html
https://security.gentoo.org/glsa/202202-03
https://security.gentoo.org/glsa/202208-14
https://ubuntu.com/security/notices/USN-5131-1
https://www.debian.org/security/2021/dsa-5026
https://www.debian.org/security/2022/dsa-5034
https://www.mozilla.org/en-US/security/advisories/mfsa2021-48/#CVE-2021-38506
https://www.mozilla.org/en-US/security/advisories/mfsa2021-49/#CVE-2021-38506
https://www.mozilla.org/security/advisories/mfsa2021-48/
https://www.mozilla.org/security/advisories/mfsa2021-49/
https://www.mozilla.org/security/advisories/mfsa2021-50/
2019624 https://bugzilla.redhat.com/show_bug.cgi?id=2019624
ASA-202111-2 https://security.archlinux.org/ASA-202111-2
ASA-202111-3 https://security.archlinux.org/ASA-202111-3
AVG-2511 https://security.archlinux.org/AVG-2511
AVG-2518 https://security.archlinux.org/AVG-2518
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
CVE-2021-38506 https://nvd.nist.gov/vuln/detail/CVE-2021-38506
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
RHSA-2021:4116 https://access.redhat.com/errata/RHSA-2021:4116
RHSA-2021:4123 https://access.redhat.com/errata/RHSA-2021:4123
RHSA-2021:4130 https://access.redhat.com/errata/RHSA-2021:4130
RHSA-2021:4132 https://access.redhat.com/errata/RHSA-2021:4132
RHSA-2021:4133 https://access.redhat.com/errata/RHSA-2021:4133
RHSA-2021:4134 https://access.redhat.com/errata/RHSA-2021:4134
RHSA-2021:4605 https://access.redhat.com/errata/RHSA-2021:4605
RHSA-2021:4607 https://access.redhat.com/errata/RHSA-2021:4607
USN-5131-1 https://usn.ubuntu.com/5131-1/
USN-5152-1 https://usn.ubuntu.com/5152-1/
USN-5248-1 https://usn.ubuntu.com/5248-1/
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-2021-38506.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:N/I:P/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-38506
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:N/I:L/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-38506
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:L/PR:N/UI:R/S:U/C:N/I:L/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-38506
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:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://security.gentoo.org/glsa/202208-14
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 0.40053
EPSS Score 0.00207
Published At March 28, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
There are no relevant records.