How severe is CVE-2021-1857?

CVE-2021-1857 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-1857 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-1857?

CVE-2021-1857 primarily affects Apple Icloud. In total, 48 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-1857?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-1857 published?

CVE-2021-1857 was published on 2021-09-08 and last updated on 2026-06-17.

CVE-2021-1857

CVE-2021-1857 is a medium-severity vulnerability in Apple Icloud with a CVSS 3.x base score of 6.5. 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-665.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-665
Affected product: Apple Icloud
Published: 2021-09-08
Last modified: 2026-06-17

Description

A memory initialization issue was addressed with improved memory handling. This issue is fixed in iTunes 12.11.3 for Windows, Security Update 2021-002 Catalina, Security Update 2021-003 Mojave, iCloud for Windows 12.3, macOS Big Sur 11.3, watchOS 7.4, tvOS 14.5, iOS 14.5 and iPadOS 14.5. Processing maliciously crafted web content may disclose sensitive user information.

Frequently asked questions

What is CVE-2021-1857?: A memory initialization issue was addressed with improved memory handling. This issue is fixed in iTunes 12.11.3 for Windows, Security Update 2021-002 Catalina, Security Update 2021-003 Mojave, iCloud for Windows 12.3, macOS Big Sur 11.3, watchOS 7.4, tvOS 14.5, iOS 14.5 and iPadOS 14.5. Processing maliciously crafted web content may disclose sensitive user information.
How severe is CVE-2021-1857?: CVE-2021-1857 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-1857 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-1857?: CVE-2021-1857 primarily affects Apple Icloud. In total, 48 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-1857?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-1857 published?: CVE-2021-1857 was published on 2021-09-08 and last updated on 2026-06-17.

References

Affected products (48)

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:mac_os_x:10.14:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.0:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.1:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.2:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.3:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.4:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.4:beta4:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.5:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:-:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-001:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-002:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-004:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-005:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-006:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2019-007:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-001:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-002:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-003:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-004:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-005:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-006:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2020-007:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2021-001:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.14.6:security_update_2021-002:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.1:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.2:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.3:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.4:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.5:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.6:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.6:-:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.6:supplemental_update:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.7:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:10.15.7:-:*:*:*:*:*:*

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…
CVE-2019-8746 — Critical (CVSS 9.8): An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Catalina 10.15, iOS…
CVE-2020-9895 — Critical (CVSS 9.8): A use after free issue was addressed with improved memory management. This issue is fixed in iOS 13.6 and iPadOS 13.6,…
CVE-2020-9850 — Critical (CVSS 9.8): A logic issue was addressed with improved restrictions. This issue is fixed in iOS 13.5 and iPadOS 13.5, tvOS 13.4.5,…
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…

All CVEs affecting Apple Icloud →

Other CWE-665 (Improper Initialization) vulnerabilities

CVE-2021-33635 — Critical (CVSS 9.8): When malicious images are pulled by isula pull, attackers can execute arbitrary code.
CVE-2022-37128 — Critical (CVSS 9.8): In D-Link DIR-816 A2_v1.10CNB04.img the network can be initialized without authentication via /goform/wizard_end.
CVE-2021-41264 — Critical (CVSS 9.8): OpenZeppelin Contracts is a library for smart contract development. In affected versions upgradeable contracts using…
CVE-2019-10196 — Critical (CVSS 9.8): A flaw was found in http-proxy-agent, prior to version 2.1.0. It was discovered http-proxy-agent passes an auth option…
CVE-2015-8367 — Critical (CVSS 9.8): The phase_one_correct function in Libraw before 0.17.1 allows attackers to cause memory errors and possibly execute…
CVE-2019-14271 — Critical (CVSS 9.8): In Docker 19.03.x before 19.03.1 linked against the GNU C Library (aka glibc), code injection can occur when the…

Browse all CWE-665 (Improper Initialization) vulnerabilities →