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CVE-2020-9818

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

8.8 HIGHActively exploited (CISA KEV)EPSS 2.29%
  1. Published9 Jun 2020
  2. Added to CISA KEV3 Nov 2021
  3. Remediation due3 May 2022
Actively exploited (CISA KEV)

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.

Added to KEV: 3 Nov 2021Federal remediation due: 3 May 2022

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 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionRequired
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

Apple iPadOS< 13.5
Apple iPhone OS≥ 13.0 < 13.5 · < 12.4.7
Apple Watchos< 6.2.5

Remediation

Fixed in
Apple iPadOS≥ 13.5
Apple iPhone OS≥ 13.5
Apple Watchos≥ 6.2.5

References

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Frequently asked

Is CVE-2020-9818 being actively exploited?

Yes. CVE-2020-9818 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 3 Nov 2021.

How severe is CVE-2020-9818?

CVE-2020-9818 has a CVSS 3.1 base score of 8.8, rated high. EPSS estimates a 2.29% probability of exploitation.

Which products are affected by CVE-2020-9818?

Affected products include Apple iPadOS, Apple iPhone OS, Apple Watchos.

How do I fix CVE-2020-9818?

Upgrade affected software to a fixed version, for example Apple iPadOS 13.5, Apple iPhone OS 13.5, Apple Watchos 6.2.5 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2020-9818 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, a risk for it never ranks below high, and the update that fixes it moves to the Emergency patch lane. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.