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CVE-2021-30666

Improper Restriction of Memory Buffer: Is CVE-2021-30666 real, exploitable, or a false positive? Here's the community verdict.

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signals

public sources

Exploited in wild
Yes
CISA KEV
Public exploit
None known
Metasploit/EDB/PoC
Base severity
8.8 High
CVSS
Exploitation prob.
3%
FIRST EPSS
Weakness
CWE-119 · Improper Restriction of Memory Buffer
CWE

Confirmed exploited in the wild. Patch this first, regardless of the base score.

baseline read

auto · not a community verdict

Real — exploited in the wild

CISA confirms active exploitation. Treat scanner hits as true positives unless your specific version or config is unaffected.

Based on CISA KEV

Confirm or dispute →

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

A buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 12.5.3. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

References

NVD MITRE CVE.org CISA KEV

Published

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Community ground truth

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In your experience, is this finding real and exploitable?

awaiting field verdicts
Real, but not a risk here
Not a real issue

Curated baseline: TruePositive's read from public sources is Real & exploitable — a starting point, not a community verdict.

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Field notes & remediation

Verdicts are the quick signal. Notes are the evidence and fixes behind them.

  • 0
    Field note · TruePositive EditorialCurated

    Apple iOS WebKit Buffer Overflow Vulnerability — Apple iOS WebKit contains a buffer-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. Listed in the CISA KEV catalog (added 2021-11-03) — confirmed exploited in the wild, not theoretical. FIRST EPSS puts the chance of exploitation in the next 30 days at ~3%. Treat it as real and prioritize remediation over triage.

  • 0
    Remediation · TruePositive EditorialCurated

    Required action for Apple iOS: Apply updates per vendor instructions. CISA set a federal remediation due date of 2021-11-17. After patching, verify the vulnerable path is no longer reachable before closing the finding.

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Related CVEs

Same weakness: CWE-119 · Improper Restriction of Memory Buffer.