[ CVE-2021-30666 · Published 8 Sep 2021 ]

Apple iOS WebKit Buffer Overflow Vulnerability

Exploited · CISA KEV CVSS 8.8 EPSS 3%No fix listed yet

[ Why it matters ]Priority signals

Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2021-11-03

[ Description ]Official description

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..

CISA: 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.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 17 Nov 2021): Apply updates per vendor instructions.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

support.apple.com/en-us/HT212341Release NotesVendor Advisory
www.cisa.gov/known-exploited-vulnerabilities-catalogThird Party AdvisoryUS Government Resource