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Vulnerability details: VCID-beh2-9nnd-qbgs
Vulnerability ID VCID-beh2-9nnd-qbgs
Aliases CVE-2021-29970
Summary A malicious webpage could have triggered a use-after-free, memory corruption, and a potentially exploitable crash. *This bug only affected Firefox when accessibility was enabled.*
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (2)
CWE-416 Use After Free
CWE-787 Out-of-bounds Write
System Score Found at
cvssv3 8.8 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-29970.json
epss 0.00247 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00247 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00247 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00247 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00247 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00247 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00247 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00247 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00247 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00247 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00247 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00247 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00312 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00312 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00312 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00312 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00312 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
epss 0.00312 https://api.first.org/data/v1/epss?cve=CVE-2021-29970
cvssv3.1 8.8 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv2 5.1 https://nvd.nist.gov/vuln/detail/CVE-2021-29970
cvssv3.1 8.8 https://nvd.nist.gov/vuln/detail/CVE-2021-29970
archlinux High https://security.archlinux.org/AVG-2148
archlinux High https://security.archlinux.org/AVG-2152
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-28
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-29
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-30
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-29970.json
https://api.first.org/data/v1/epss?cve=CVE-2021-29970
https://bugzilla.mozilla.org/show_bug.cgi?id=1709976
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-29969
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-29970
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-29976
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-30547
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://security.gentoo.org/glsa/202202-03
https://security.gentoo.org/glsa/202208-14
https://www.mozilla.org/security/advisories/mfsa2021-28/
https://www.mozilla.org/security/advisories/mfsa2021-29/
https://www.mozilla.org/security/advisories/mfsa2021-30/
1982013 https://bugzilla.redhat.com/show_bug.cgi?id=1982013
ASA-202107-20 https://security.archlinux.org/ASA-202107-20
ASA-202107-21 https://security.archlinux.org/ASA-202107-21
AVG-2148 https://security.archlinux.org/AVG-2148
AVG-2152 https://security.archlinux.org/AVG-2152
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:*:*:*:*:*:*:*:*
CVE-2021-29970 https://nvd.nist.gov/vuln/detail/CVE-2021-29970
mfsa2021-28 https://www.mozilla.org/en-US/security/advisories/mfsa2021-28
mfsa2021-29 https://www.mozilla.org/en-US/security/advisories/mfsa2021-29
mfsa2021-30 https://www.mozilla.org/en-US/security/advisories/mfsa2021-30
RHSA-2021:2740 https://access.redhat.com/errata/RHSA-2021:2740
RHSA-2021:2741 https://access.redhat.com/errata/RHSA-2021:2741
RHSA-2021:2742 https://access.redhat.com/errata/RHSA-2021:2742
RHSA-2021:2743 https://access.redhat.com/errata/RHSA-2021:2743
RHSA-2021:2881 https://access.redhat.com/errata/RHSA-2021:2881
RHSA-2021:2882 https://access.redhat.com/errata/RHSA-2021:2882
RHSA-2021:2883 https://access.redhat.com/errata/RHSA-2021:2883
RHSA-2021:2914 https://access.redhat.com/errata/RHSA-2021:2914
USN-5011-1 https://usn.ubuntu.com/5011-1/
USN-5058-1 https://usn.ubuntu.com/5058-1/
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-29970.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:L/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:H/Au:N/C:P/I:P/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2021-29970
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:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2021-29970
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 0.47962
EPSS Score 0.00247
Published At July 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:09:45.603215+00:00 Mozilla Importer Import https://github.com/mozilla/foundation-security-advisories/blob/master/announce/2021/mfsa2021-28.yml 37.0.0