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Vulnerability details: VCID-bxjd-dm71-4ua4
Vulnerability ID VCID-bxjd-dm71-4ua4
Aliases CVE-2021-23975
Summary The developer page about:memory has a Measure function for exploring what object types the browser has allocated and their sizes. When this function was invoked we incorrectly called the sizeof function, instead of using the API method that checks for invalid pointers.
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (1)
CWE-862 Missing Authorization
System Score Found at
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
epss 0.00287 https://api.first.org/data/v1/epss?cve=CVE-2021-23975
cvssv3.1 6.5 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv2 4.3 https://nvd.nist.gov/vuln/detail/CVE-2021-23975
cvssv3.1 6.5 https://nvd.nist.gov/vuln/detail/CVE-2021-23975
archlinux High https://security.archlinux.org/AVG-1599
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-07
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-23975
https://bugzilla.mozilla.org/show_bug.cgi?id=1685145
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://security.gentoo.org/glsa/202104-10
https://www.mozilla.org/security/advisories/mfsa2021-07/
AVG-1599 https://security.archlinux.org/AVG-1599
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-2021-23975 https://nvd.nist.gov/vuln/detail/CVE-2021-23975
mfsa2021-07 https://www.mozilla.org/en-US/security/advisories/mfsa2021-07
USN-4756-1 https://usn.ubuntu.com/4756-1/
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N 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-2021-23975
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:H/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-23975
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 0.51853
EPSS Score 0.00287
Published At Sept. 21, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:09:48.867260+00:00 Mozilla Importer Import https://github.com/mozilla/foundation-security-advisories/blob/master/announce/2021/mfsa2021-07.yml 37.0.0