Apple iOS, iPadOS, macOS Use-After-Free Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2021-11-03
• EPSS: 13% chance of exploitation in the next 30 days (higher than 96% of CVEs)

[ Description ]Official description

A use after free issue was addressed with improved memory management. This issue is fixed in iOS 14.8 and iPadOS 14.8, macOS Big Sur 11.6. 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, iPadOS, and macOS WebKit contain a use-after-free 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

• seclists.org/fulldisclosure/2021/Sep/25Mailing ListThird Party Advisory
• seclists.org/fulldisclosure/2021/Sep/27Mailing ListThird Party Advisory
• seclists.org/fulldisclosure/2021/Sep/29Mailing ListThird Party Advisory
• seclists.org/fulldisclosure/2021/Sep/38Mailing ListThird Party Advisory
• seclists.org/fulldisclosure/2021/Sep/39Mailing ListThird Party Advisory
• seclists.org/fulldisclosure/2021/Sep/50Mailing ListThird Party Advisory
• www.openwall.com/lists/oss-security/2021/09/20/1Mailing List
• www.openwall.com/lists/oss-security/2021/10/26/9Mailing List
• www.openwall.com/lists/oss-security/2021/10/27/1Mailing List
• www.openwall.com/lists/oss-security/2021/10/27/2Mailing List
• www.openwall.com/lists/oss-security/2021/10/27/4Mailing List
• lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/messag…Release Notes
• lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/messag…Release Notes
• support.apple.com/en-us/HT212804Third Party Advisory
• support.apple.com/en-us/HT212807Third Party Advisory
• support.apple.com/kb/HT212824Third Party Advisory
• www.debian.org/security/2021/dsa-4975Mailing ListThird Party Advisory
• www.debian.org/security/2021/dsa-4976Mailing ListThird Party Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource