CVE-2018-18366

CVE-2018-18366 is a medium-severity vulnerability in Symantec Endpoint Protection 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-908.

Key facts

• Severity: Medium (CVSS 3.x base score 6.5)
• CVSS v2: 2.1
• EPSS exploit prediction: 0% (31st percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-908
• Affected product: Symantec Endpoint Protection
• Published: 2019-04-25
• Last modified: 2026-06-17

Description

Symantec Norton Security prior to 22.16.3, SEP (Windows client) prior to and including 12.1 RU6 MP9, and prior to 14.2 RU1, SEP SBE prior to Cloud Agent 3.00.31.2817, NIS-22.15.2.22, SEP-12.1.7484.7002 and SEP Cloud prior to 22.16.3 may be susceptible to a kernel memory disclosure, which is a type of issue where a specially crafted IRP request can cause the driver to return uninitialized memory.

Frequently asked questions

What is CVE-2018-18366?

Symantec Norton Security prior to 22.16.3, SEP (Windows client) prior to and including 12.1 RU6 MP9, and prior to 14.2 RU1, SEP SBE prior to Cloud Agent 3.00.31.2817, NIS-22.15.2.22, SEP-12.1.7484.7002 and SEP Cloud prior to 22.16.3 may be susceptible to a kernel memory disclosure, which is a type of issue where a specially crafted IRP request can cause the driver to return uninitialized memory.

How severe is CVE-2018-18366?

CVE-2018-18366 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2018-18366 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-18366?

CVE-2018-18366 primarily affects Symantec Endpoint Protection. In total, 53 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-18366?

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

When was CVE-2018-18366 published?

CVE-2018-18366 was published on 2019-04-25 and last updated on 2026-06-17.

References

• http://www.securityfocus.com/bid/107994
• https://support.symantec.com/en_US/article.SYMSA1479.html

Affected products (53)

• cpe:2.3:a:symantec:endpoint_protection:11.0:*:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:mr1:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:mr2:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:mr3:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:mr4:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:mr4-mp2:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:ru5:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:ru6:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:ru6-mp1:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:ru6-mp2:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:ru6-mp3:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:ru6a:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:ru7:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:ru7-mp1:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:ru7-mp2:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:ru7-mp4:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:ru7-mp4a:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:11.0:ry7-mp3:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:*:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru1:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru1-mp1:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru2:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru2-mp1:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru3:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru4:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru4-mp1:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru4-mp1a:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru4-mp1b:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru4a:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru5:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru6:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru6-mp1:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru6-mp10:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru6-mp2:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru6-mp3:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru6-mp4:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru6-mp5:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru6-mp6:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru6-mp7:*:*:*:windows:*:*
• cpe:2.3:a:symantec:endpoint_protection:12.1:ru6-mp8:*:*:*:windows:*:*

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