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Vulnerability details: VCID-myvt-vay8-aaaj
Vulnerability ID VCID-myvt-vay8-aaaj
Aliases CVE-2021-4129
Summary Mozilla developers and community members Julian Hector, Randell Jesup, Gabriele Svelto, Tyson Smith, Christian Holler, and Masayuki Nakano reported memory safety bugs present in Firefox 94. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 95, Firefox ESR < 91.4.0, and Thunderbird < 91.4.0.
Status Published
Exploitability 0.5
Weighted Severity 8.8
Risk 4.4
Affected and Fixed Packages Package Details
Weaknesses (2)
CWE-787 Out-of-bounds Write
CWE-120 Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
System Score Found at
rhas Important https://access.redhat.com/errata/RHSA-2021:5013
rhas Important https://access.redhat.com/errata/RHSA-2021:5014
rhas Important https://access.redhat.com/errata/RHSA-2021:5015
rhas Important https://access.redhat.com/errata/RHSA-2021:5016
rhas Important https://access.redhat.com/errata/RHSA-2021:5017
rhas Important https://access.redhat.com/errata/RHSA-2021:5045
rhas Important https://access.redhat.com/errata/RHSA-2021:5046
rhas Important https://access.redhat.com/errata/RHSA-2021:5047
rhas Important https://access.redhat.com/errata/RHSA-2021:5048
rhas Important https://access.redhat.com/errata/RHSA-2021:5055
cvssv3 9.8 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-4129.json
epss 0.00240 https://api.first.org/data/v1/epss?cve=CVE-2021-4129
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epss 0.00298 https://api.first.org/data/v1/epss?cve=CVE-2021-4129
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epss 0.00902 https://api.first.org/data/v1/epss?cve=CVE-2021-4129
cvssv3.1 9.8 https://bugzilla.mozilla.org/buglist.cgi?bug_id=1393362%2C1736046%2C1736751%2C1737009%2C1739372%2C1739421
ssvc Track https://bugzilla.mozilla.org/buglist.cgi?bug_id=1393362%2C1736046%2C1736751%2C1737009%2C1739372%2C1739421
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 9.8 https://nvd.nist.gov/vuln/detail/CVE-2021-4129
cvssv3.1 9.8 https://nvd.nist.gov/vuln/detail/CVE-2021-4129
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-52
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-53
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-54
cvssv3.1 9.8 https://www.mozilla.org/security/advisories/mfsa2021-52/
ssvc Track https://www.mozilla.org/security/advisories/mfsa2021-52/
cvssv3.1 9.8 https://www.mozilla.org/security/advisories/mfsa2021-53/
ssvc Track https://www.mozilla.org/security/advisories/mfsa2021-53/
cvssv3.1 9.8 https://www.mozilla.org/security/advisories/mfsa2021-54/
ssvc Track https://www.mozilla.org/security/advisories/mfsa2021-54/
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-4129.json
https://api.first.org/data/v1/epss?cve=CVE-2021-4129
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1393362%2C1736046%2C1736751%2C1737009%2C1739372%2C1739421
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://www.mozilla.org/security/advisories/mfsa2021-52/
https://www.mozilla.org/security/advisories/mfsa2021-53/
https://www.mozilla.org/security/advisories/mfsa2021-54/
2030116 https://bugzilla.redhat.com/show_bug.cgi?id=2030116
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-2021-4129 https://nvd.nist.gov/vuln/detail/CVE-2021-4129
mfsa2021-52 https://www.mozilla.org/en-US/security/advisories/mfsa2021-52
mfsa2021-53 https://www.mozilla.org/en-US/security/advisories/mfsa2021-53
mfsa2021-54 https://www.mozilla.org/en-US/security/advisories/mfsa2021-54
RHSA-2021:5013 https://access.redhat.com/errata/RHSA-2021:5013
RHSA-2021:5014 https://access.redhat.com/errata/RHSA-2021:5014
RHSA-2021:5015 https://access.redhat.com/errata/RHSA-2021:5015
RHSA-2021:5016 https://access.redhat.com/errata/RHSA-2021:5016
RHSA-2021:5017 https://access.redhat.com/errata/RHSA-2021:5017
RHSA-2021:5045 https://access.redhat.com/errata/RHSA-2021:5045
RHSA-2021:5046 https://access.redhat.com/errata/RHSA-2021:5046
RHSA-2021:5047 https://access.redhat.com/errata/RHSA-2021:5047
RHSA-2021:5048 https://access.redhat.com/errata/RHSA-2021:5048
RHSA-2021:5055 https://access.redhat.com/errata/RHSA-2021:5055
USN-5246-1 https://usn.ubuntu.com/5246-1/
USN-5248-1 https://usn.ubuntu.com/5248-1/
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-4129.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:N/S:U/C:H/I:H/A:H Found at https://bugzilla.mozilla.org/buglist.cgi?bug_id=1393362%2C1736046%2C1736751%2C1737009%2C1739372%2C1739421
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: SSVCv2/E:N/A:Y/T:T/P:M/B:A/M:M/D:T/2025-04-16T15:56:25Z/ Found at https://bugzilla.mozilla.org/buglist.cgi?bug_id=1393362%2C1736046%2C1736751%2C1737009%2C1739372%2C1739421
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2021-4129
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:H/I:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2021-4129
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:H/I:H/A:H Found at https://www.mozilla.org/security/advisories/mfsa2021-52/
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: SSVCv2/E:N/A:Y/T:T/P:M/B:A/M:M/D:T/2025-04-16T15:56:25Z/ Found at https://www.mozilla.org/security/advisories/mfsa2021-52/
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://www.mozilla.org/security/advisories/mfsa2021-53/
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: SSVCv2/E:N/A:Y/T:T/P:M/B:A/M:M/D:T/2025-04-16T15:56:25Z/ Found at https://www.mozilla.org/security/advisories/mfsa2021-53/
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://www.mozilla.org/security/advisories/mfsa2021-54/
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: SSVCv2/E:N/A:Y/T:T/P:M/B:A/M:M/D:T/2025-04-16T15:56:25Z/ Found at https://www.mozilla.org/security/advisories/mfsa2021-54/
Exploit Prediction Scoring System (EPSS)
Percentile 0.62405
EPSS Score 0.00240
Published At Nov. 1, 2024, midnight
Date Actor Action Source VulnerableCode Version
There are no relevant records.