Threats / Apple / CVE-2021-30952
CVE-2021-30952
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-09-19
Apple Multiple Products vulnerability
Integer overflow vulnerability in Apple's web content processing across tvOS, macOS, Safari, iPadOS, and watchOS enables arbitrary code execution when processing maliciously crafted web content.
Verdict
Today item — known-exploited.
An integer overflow in web content handling allows attackers to achieve code execution on affected Apple platforms. Active exploitation in the wild demonstrates practical threat despite low EPSS score. Patching is critical for all affected products.
CISA KEV Yes · 2026-03-054EPSS 0.06964 (verify live)5CVSS 8.8 (CISA)3CISA SSVC Exploitation: active · Automatable: no · Impact: total3
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
3 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-03-05).
Probability (EPSS)
EPSS 0.06964 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 8.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) · Affected: Apple, Multiple Products. Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
Weakness (CWE)
Mapped to CWE-190 Integer Overflow — weakness family: Memory safety.CWE assignment from the public NVD record (may be stale); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 1654 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft malicious web content designed to trigger integer overflow in the target's browser or web view.
Business
User devices become compromised through routine web browsing, exposing personal data and enabling lateral movement within corporate networks.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I exploit the overflow to break memory safety constraints and execute arbitrary code with the privileges of the affected application.
Business
Attackers gain persistent access to devices, potentially installing malware, stealing credentials, or establishing command-and-control infrastructure.
3
Lateral reach — past segmentation narrative 3
Attacker
I target users across multiple Apple ecosystems—phones, tablets, computers, watches, and streaming devices—through a single malicious webpage or compromised ad network.
Business
Organizations face widespread device compromise across their Apple infrastructure, complicating incident response and increasing breach scope.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05
Coverage & confidence
— what we know, and what we don’tEstablished (cited)
Coverage gaps — stated, not hidden
Disclosure & credit2
Catalogued by appleCNA
Credited with finding itNo finder is named in the public CVE record or the scanned vendor advisory — attribution scoped to the sources checked.
Found an error? Propose a correction.
A correction is a cited counter-claim — it must cite a source,
gets reviewed by a second human, and is never auto-applied. See the
correction convention and our identity
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