How severe is CVE-2020-36521?

CVE-2020-36521 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-2020-36521 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-36521?

CVE-2020-36521 primarily affects Apple Icloud. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-36521?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-36521 published?

CVE-2020-36521 was published on 2022-09-23 and last updated on 2026-06-17.

CVE-2020-36521

CVE-2020-36521 is a high-severity vulnerability in Apple Icloud with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Severity: High (CVSS 3.x base score 7.1)
EPSS exploit prediction: 0% (33rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Apple Icloud
Published: 2022-09-23
Last modified: 2026-06-17

Description

An out-of-bounds read was addressed with improved input validation. This issue is fixed in iCloud for Windows 11.4, iOS 14.0 and iPadOS 14.0, watchOS 7.0, tvOS 14.0, iCloud for Windows 7.21, iTunes for Windows 12.10.9. Processing a maliciously crafted tiff file may lead to a denial-of-service or potentially disclose memory contents.

Frequently asked questions

What is CVE-2020-36521?: An out-of-bounds read was addressed with improved input validation. This issue is fixed in iCloud for Windows 11.4, iOS 14.0 and iPadOS 14.0, watchOS 7.0, tvOS 14.0, iCloud for Windows 7.21, iTunes for Windows 12.10.9. Processing a maliciously crafted tiff file may lead to a denial-of-service or potentially disclose memory contents.
How severe is CVE-2020-36521?: CVE-2020-36521 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2020-36521 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-36521?: CVE-2020-36521 primarily affects Apple Icloud. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-36521?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-36521 published?: CVE-2020-36521 was published on 2022-09-23 and last updated on 2026-06-17.

References

Affected products (7)

cpe:2.3:a:apple:icloud:*:*:*:*:*:windows:*:*
cpe:2.3:a:apple:itunes:*:*:*:*:*:windows:*:*
cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*

More vulnerabilities in Apple Icloud

CVE-2019-8756 — Critical (CVSS 9.8): Multiple memory corruption issues were addressed with improved input validation. This issue is fixed in macOS Catalina…
CVE-2019-8749 — Critical (CVSS 9.8): Multiple memory corruption issues were addressed with improved input validation. This issue is fixed in macOS Catalina…
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CVE-2020-3911 — Critical (CVSS 9.8): A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 13.4 and iPadOS 13.4, macOS…

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Other CWE-125 (Out-of-bounds Read) vulnerabilities

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CVE-2024-22004 — Critical (CVSS 10.0): Due to length check, an attacker with privilege access on a Linux Nonsecure operating system can trigger a…
CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…

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