CVE-2021-30666

criticalknown exploitedcovered by 1 sourcefirst seen 2021-11-03

Actively exploited. CVE-2021-30666 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03) — exploitation has been observed in the wild, and US federal agencies are required to remediate it under BOD 22-01. Treat patching as urgent.

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.

CSIRTS triage

What: There is a buffer-overflow vulnerability that leads to code execution when processing maliciously crafted web content.
Who is affected: Deployments of Apple iOS WebKit, including Apple Safari and other products relying on WebKit.
Urgency: Remediation is urgent due to active exploitation and critical severity.
Action: Update to the latest version of iOS WebKit.

AI-assisted analysis generated from the source advisory — verify against the original.

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Exploitation outlook

Exploitation confirmedAlready exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 86% of all EPSS-scored CVEs.

Advisory coverage (1)

criticalexploitedCVE-2021-30666: Apple iOS WebKit Buffer Overflow Vulnerabilitycisa-kev · 2021-11-03

External references

NVD record for CVE-2021-30666

CVE.org record

CISA KEV catalog

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