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Vulnerability details: VCID-wgmv-rr1v-5ub9
Vulnerability ID VCID-wgmv-rr1v-5ub9
Aliases CVE-2021-23956
Summary An ambiguous file picker design could have confused users who intended to select and upload a single file into uploading a whole directory. This was addressed by adding a new prompt.
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (0)
There are no known CWE.
System Score Found at
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
epss 0.00284 https://api.first.org/data/v1/epss?cve=CVE-2021-23956
cvssv2 4.3 https://nvd.nist.gov/vuln/detail/CVE-2021-23956
cvssv3.1 6.5 https://nvd.nist.gov/vuln/detail/CVE-2021-23956
archlinux High https://security.archlinux.org/AVG-1492
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-03
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-23956
https://bugzilla.mozilla.org/show_bug.cgi?id=1338637
https://www.mozilla.org/security/advisories/mfsa2021-03/
ASA-202102-1 https://security.archlinux.org/ASA-202102-1
AVG-1492 https://security.archlinux.org/AVG-1492
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:*:*:*:*:*:*:*:*
CVE-2021-23956 https://nvd.nist.gov/vuln/detail/CVE-2021-23956
mfsa2021-03 https://www.mozilla.org/en-US/security/advisories/mfsa2021-03
USN-4717-1 https://usn.ubuntu.com/4717-1/
No exploits are available.
Vector: AV:N/AC:M/Au:N/C:P/I:N/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-23956
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-2021-23956
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 0.51463
EPSS Score 0.00284
Published At July 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:09:50.361912+00:00 Mozilla Importer Import https://github.com/mozilla/foundation-security-advisories/blob/master/announce/2021/mfsa2021-03.yml 37.0.0