How severe is CVE-2018-4227?

CVE-2018-4227 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2018-4227 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-4227?

CVE-2018-4227 primarily affects Apple Iphone Os. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-4227?

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-2018-4227 published?

CVE-2018-4227 was published on 2018-06-08 and last updated on 2026-06-17.

CVE-2018-4227

CVE-2018-4227 is a high-severity vulnerability in Apple Iphone Os with a CVSS 3.x base score of 7.5. 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-319.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (77th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-319
Affected product: Apple Iphone Os
Published: 2018-06-08
Last modified: 2026-06-17

Description

An issue was discovered in certain Apple products. iOS before 11.4 is affected. macOS before 10.13.5 is affected. The issue involves the "Mail" component. It allows remote attackers to read the cleartext content of S/MIME encrypted messages via direct exfiltration.

Frequently asked questions

What is CVE-2018-4227?: An issue was discovered in certain Apple products. iOS before 11.4 is affected. macOS before 10.13.5 is affected. The issue involves the "Mail" component. It allows remote attackers to read the cleartext content of S/MIME encrypted messages via direct exfiltration.
How severe is CVE-2018-4227?: CVE-2018-4227 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2018-4227 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-4227?: CVE-2018-4227 primarily affects Apple Iphone Os. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-4227?: 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-2018-4227 published?: CVE-2018-4227 was published on 2018-06-08 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*

More vulnerabilities in Apple Iphone Os

CVE-2025-43300 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS…
CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
CVE-2025-24085 — Critical (CVSS 10.0): A use after free issue was addressed with improved memory management. This issue is fixed in iOS 18.3 and iPadOS 18.3,…
CVE-2022-32845 — Critical (CVSS 10.0): This issue was addressed with improved checks. This issue is fixed in watchOS 8.7, iOS 15.6 and iPadOS 15.6, macOS…
CVE-2019-8779 — Critical (CVSS 10.0): A logic issue applied the incorrect restrictions. This issue was addressed by updating the logic to apply the correct…
CVE-2018-4310 — Critical (CVSS 10.0): An access issue was addressed with additional sandbox restrictions. This issue affected versions prior to iOS 12, macOS…

All CVEs affecting Apple Iphone Os →

Other CWE-319 (Cleartext Transmission of Sensitive Information) vulnerabilities

CVE-2025-4378 — Critical (CVSS 10.0): Cleartext Transmission of Sensitive Information, Use of Hard-coded Credentials vulnerability in Ataturk University…
CVE-2025-47419 — Critical (CVSS 10.0): Cleartext Transmission of Sensitive Information vulnerability in Crestron Automate VX allows Sniffing Network…
CVE-2026-48902 — Critical (CVSS 9.8): The password and username reset features created plain http links for https connections if the "Force SSL" flag wasn't…
CVE-2025-34271 — Critical (CVSS 9.8): Nagios Log Server versions prior to 2024R2.0.2 contain a vulnerability in the cluster manager component when…
CVE-2025-32880 — Critical (CVSS 9.8): An issue was discovered on COROS PACE 3 devices through 3.0808.0. It implements a function to connect the watch to a…
CVE-2025-26199 — Critical (CVSS 9.8): CloudClassroom-PHP-Project v1.0 is affected by an insecure credential transmission vulnerability. The application…

Browse all CWE-319 (Cleartext Transmission of Sensitive Information) vulnerabilities →