How severe is CVE-2018-4240?

CVE-2018-4240 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 none, integrity none, and availability high.

Is CVE-2018-4240 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-4240?

CVE-2018-4240 primarily affects Apple Iphone Os. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-4240?

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

When was CVE-2018-4240 published?

CVE-2018-4240 was published on 2018-06-08 and last updated on 2026-06-17.

CVE-2018-4240

CVE-2018-4240 is a medium-severity vulnerability in Apple Iphone Os 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-20.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 7% (93rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
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. tvOS before 11.4 is affected. watchOS before 4.3.1 is affected. The issue involves the "Messages" component. It allows remote attackers to cause a denial of service via a crafted message.

Frequently asked questions

What is CVE-2018-4240?: An issue was discovered in certain Apple products. iOS before 11.4 is affected. macOS before 10.13.5 is affected. tvOS before 11.4 is affected. watchOS before 4.3.1 is affected. The issue involves the "Messages" component. It allows remote attackers to cause a denial of service via a crafted message.
How severe is CVE-2018-4240?: CVE-2018-4240 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 none, integrity none, and availability high.
Is CVE-2018-4240 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-4240?: CVE-2018-4240 primarily affects Apple Iphone Os. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-4240?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-4240 published?: CVE-2018-4240 was published on 2018-06-08 and last updated on 2026-06-17.

References

Affected products (4)

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

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