CVEs / CVE-2020-9818
CVE-2020-9818: Apple iOS, iPadOS, and watchOS Out-of-Bounds Write Vulnerability
- Known exploited in the CISA KEV catalog since 3 Nov 2021
- high 8.8 CVSS 3.1 (NVD)
- EPSS 2.34% chance of exploitation in the next 30 days, higher than 83% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
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.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Apple iOS | from unspecified, before iOS 13.5 and iPadOS 13.5 | iOS 13.5 and iPadOS 13.5 |
| Apple iOS-1 | from unspecified, before iOS 12.4.7 | iOS 12.4.7 |
| Apple watchOS | from unspecified, before watchOS 6.2.5 | watchOS 6.2.5 |
Exploitation
| In CISA KEV since | 3 Nov 2021 |
|---|---|
| Due date for US federal agencies | 3 May 2022 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply updates per vendor instructions. |
Severity
| CVSS 3.1 | 8.8 highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-787 |
References
- CVE-2020-9818 on NVD
- CVE-2020-9818 in the CISA KEV catalog
- https://support.apple.com/HT211168 Release Notes, Vendor Advisory
- https://support.apple.com/HT211169 Release Notes, Vendor Advisory
- https://support.apple.com/HT211175 Release Notes, Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-9818 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.