Known exploited · Apple
CVE-2023-42917: Apple Multiple Products WebKit Memory Corruption Vulnerability
What it is
Apple iOS, iPadOS, macOS, and Safari WebKit contain a memory corruption 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.
- Vendor
- Apple
- Product
- Multiple Products
- Added to KEV
- December 4, 2023
- CISA due date
- December 25, 2023
- Ransomware use
- Unknown
- Weakness
- CWE-787: Out-of-bounds Write
What CISA requires
Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Forensic triage
No
What to do now
- Find every instance of Multiple Products you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before December 25, 2023 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
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Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.