CVE-2020-9818
Apple iOS, iPadOS, and watchOS Out-of-Bounds Write Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 3 May 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
Description
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 13.5 and iPadOS 13.5, iOS 12.4.7, watchOS 6.2.5. Processing a maliciously crafted mail message may lead to unexpected memory modification or application termination.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 2.34% probability · 84th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 3 November 2021 · due 3 May 2022
- Weakness
- CWE-787
- Affected
- apple/ipados · apple/iphone os · apple/watchos
- Source
- product-security@apple.com
EPSS 2.3% since 30 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2020-9818
References
- https://support.apple.com/HT211168Release Notes, Vendor Advisory
- https://support.apple.com/HT211169Release Notes, Vendor Advisory
- https://support.apple.com/HT211175Release Notes, Vendor Advisory
- https://support.apple.com/HT211168Release Notes, Vendor Advisory
- https://support.apple.com/HT211169Release Notes, Vendor Advisory
- https://support.apple.com/HT211175Release Notes, Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-9818US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.