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CVE-2020-9818

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in...

8.8 HighIn KEV

CVE-2020-9818 is a high vulnerability (CVSS 8.8) in Apple Ios, published June 9, 2020. CISA lists it as known to be exploited, since November 3, 2021. EUVD reports exploitation since November 3, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.34%, the 83rd percentile. No source names a fixed version.

What does this mean?
Severity
8.8 HighCVSS 3.1, NVD
Exploit chance
2.34%EPSS, 83rd percentile
Exploitation
ExploitedCISA KEV,
Fixed in
No fix listedNo source names one

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.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
Required

What an attacker can affect

Confidentiality
High
Integrity
High
Availability
High

Exploit likelihood

2.34%Up 2.2 points since Apr 14, 2021
90%50%10%1%

Affected products

What each source reports

NVD Score used8.8

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.

Record
CVE-2020-9818
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 2.0
6.8 MediumAV:N/AC:M/Au:N/C:P/I:P/A:P
Weakness
CWE-787
Updated
2026-11-02
CVE List8.8

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.

Record
CVE-2020-9818
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness
CWE-787
Updated
2026-11-02
EUVDEUVD-2020-305978.8

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.

Record
EUVD-2020-30597
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Updated
2026-11-02
GitHub AdvisoriesGHSA-r647-89qj-xwmp8.8

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in...

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.

Record
GHSA-r647-89qj-xwmp
CVSS 3.1
8.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness
CWE-787
Updated
2026-11-02
CISA KEVNo score

Apple iOS, iPadOS, and watchOS Out-of-Bounds Write Vulnerability

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.

Record
CVE-2020-9818
Weakness
CWE-787
Updated
2026-11-02

History

History
RecordedChangedSources
exploitation
first indexedCVE List, EUVD, GitHub Advisories, CISA KEV, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

References

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