Known exploited · Apple
CVE-2020-9818: Apple iOS, iPadOS, and watchOS Out-of-Bounds Write Vulnerability
What it is
Apple iOS, iPadOS, and watchOS Mail contains an out-of-bounds write vulnerability which may allow memory modification or application termination when processing a maliciously crafted mail message.
- Vendor
- Apple
- Product
- iOS, iPadOS, and watchOS
- Added to KEV
- November 3, 2021
- CISA due date
- May 3, 2022
- Ransomware use
- Unknown
- Weakness
- CWE-787: Out-of-bounds Write
What CISA requires
Apply updates per vendor instructions.
Forensic triage
No
What to do now
- Find every instance of iOS, iPadOS, and watchOS you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before May 3, 2022 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.