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Vulnerability details: VCID-y8x6-pdyn-n7b9
Vulnerability ID VCID-y8x6-pdyn-n7b9
Aliases CVE-2021-30663
Summary An integer overflow was addressed with improved input validation. This issue is fixed in iOS 14.5.1 and iPadOS 14.5.1, tvOS 14.6, iOS 12.5.3, Safari 14.1.1, macOS Big Sur 11.3.1. Processing maliciously crafted web content may lead to arbitrary code execution.
Status Published
Exploitability 2.0
Weighted Severity 8.0
Risk 10.0
Affected and Fixed Packages Package Details
Weaknesses (1)
CWE-190 Integer Overflow or Wraparound
System Score Found at
cvssv3 8.8 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-30663.json
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
epss 0.00117 https://api.first.org/data/v1/epss?cve=CVE-2021-30663
cvssv2 6.8 https://nvd.nist.gov/vuln/detail/CVE-2021-30663
cvssv3.1 8.8 https://nvd.nist.gov/vuln/detail/CVE-2021-30663
archlinux High https://security.archlinux.org/AVG-2220
archlinux High https://security.archlinux.org/AVG-2221
cvssv3.1 7.8 https://support.apple.com/en-us/HT212335
ssvc Attend https://support.apple.com/en-us/HT212335
cvssv3.1 7.8 https://support.apple.com/en-us/HT212336
ssvc Attend https://support.apple.com/en-us/HT212336
cvssv3.1 7.8 https://support.apple.com/en-us/HT212341
ssvc Attend https://support.apple.com/en-us/HT212341
cvssv3.1 7.8 https://support.apple.com/en-us/HT212532
ssvc Attend https://support.apple.com/en-us/HT212532
cvssv3.1 7.8 https://support.apple.com/en-us/HT212534
ssvc Attend https://support.apple.com/en-us/HT212534
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-30663.json
https://api.first.org/data/v1/epss?cve=CVE-2021-30663
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21775
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21779
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-30663
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-30665
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-30689
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-30720
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-30734
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-30744
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-30749
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-30758
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-30795
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-30797
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-30799
1986872 https://bugzilla.redhat.com/show_bug.cgi?id=1986872
ASA-202107-67 https://security.archlinux.org/ASA-202107-67
ASA-202107-68 https://security.archlinux.org/ASA-202107-68
AVG-2220 https://security.archlinux.org/AVG-2220
AVG-2221 https://security.archlinux.org/AVG-2221
cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
CVE-2021-30663 https://nvd.nist.gov/vuln/detail/CVE-2021-30663
HT212335 https://support.apple.com/en-us/HT212335
HT212336 https://support.apple.com/en-us/HT212336
HT212341 https://support.apple.com/en-us/HT212341
HT212532 https://support.apple.com/en-us/HT212532
HT212534 https://support.apple.com/en-us/HT212534
RHSA-2021:4381 https://access.redhat.com/errata/RHSA-2021:4381
RHSA-2025:10364 https://access.redhat.com/errata/RHSA-2025:10364
USN-5024-1 https://usn.ubuntu.com/5024-1/
Data source KEV
Date added Nov. 3, 2021
Description Apple iOS, iPadOS, macOS, tvOS, and Safari WebKit contain an integer overflow vulnerability that leads to code execution when processing maliciously crafted web content. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.
Required action Apply updates per vendor instructions.
Due date Nov. 17, 2021
Note 
https://nvd.nist.gov/vuln/detail/CVE-2021-30663
Ransomware campaign use Unknown
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-2021-30663.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: AV:N/AC:M/Au:N/C:P/I:P/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2021-30663
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-2021-30663
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:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Found at https://support.apple.com/en-us/HT212335
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:A/A:N/T:T/P:M/B:A/M:M/D:A/2025-02-04T16:23:07Z/ Found at https://support.apple.com/en-us/HT212335
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Found at https://support.apple.com/en-us/HT212336
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:A/A:N/T:T/P:M/B:A/M:M/D:A/2025-02-04T16:23:07Z/ Found at https://support.apple.com/en-us/HT212336
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Found at https://support.apple.com/en-us/HT212341
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:A/A:N/T:T/P:M/B:A/M:M/D:A/2025-02-04T16:23:07Z/ Found at https://support.apple.com/en-us/HT212341
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Found at https://support.apple.com/en-us/HT212532
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:A/A:N/T:T/P:M/B:A/M:M/D:A/2025-02-04T16:23:07Z/ Found at https://support.apple.com/en-us/HT212532
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Found at https://support.apple.com/en-us/HT212534
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:A/A:N/T:T/P:M/B:A/M:M/D:A/2025-02-04T16:23:07Z/ Found at https://support.apple.com/en-us/HT212534
Exploit Prediction Scoring System (EPSS)
Percentile 0.31257
EPSS Score 0.00117
Published At July 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:29:18.018558+00:00 Alpine Linux Importer Import https://secdb.alpinelinux.org/v3.18/community.json 37.0.0