How severe is CVE-2020-9818?

CVE-2020-9818 has a CVSS 3.1 base score of 8.8 (HIGH). EPSS estimates a 2.3% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2020-9818: Apple iOS, iPadOS, and watchOS Out-of-Bounds Write

CISA Known Exploited Vulnerabilities

Apple iOS, iPadOS, and watchOS Out-of-Bounds Write Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2021-11-03

Remediation due

2022-05-03

Required action
Apply updates per vendor instructions.

CISA notes
https://nvd.nist.gov/vuln/detail/CVE-2020-9818

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.

Severity

CVSS 3.1 · CISA8.8 HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

SSVC · CISA-ADP

Exploitationactive

Automatableno

Technical impacttotal

Affected Products

Vendor	Product	Affected versions
Apple	iOS	unspecified to <iOS 13.5 and iPadOS 13.5
Apple	iOS-1	unspecified to <iOS 12.4.7
Apple	watchOS	unspecified to <watchOS 6.2.5

References

3 Links

Other references

Record Details

Published

2020-06-09

Last updated

2025-12-20

Assigner (CNA)

apple

Credited to

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CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.