How severe is CVE-2018-5243?

CVE-2018-5243 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 none, integrity none, and availability high.

Is CVE-2018-5243 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-5243?

CVE-2018-5243 affects Symantec Encryption Management Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-5243?

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-2018-5243 published?

CVE-2018-5243 was published on 2018-08-20 and last updated on 2026-06-17.

CVE-2018-5243

CVE-2018-5243 is a high-severity vulnerability in Symantec Encryption Management Server 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-400.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: Symantec Encryption Management Server
Published: 2018-08-20
Last modified: 2026-06-17

Description

The Symantec Encryption Management Server (SEMS) product, prior to version 3.4.2 MP1, may be susceptible to a denial of service (DoS) exploit. A DoS attack is a type of attack whereby the perpetrator attempts to make a particular machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a specific host within a network.

Frequently asked questions

What is CVE-2018-5243?: The Symantec Encryption Management Server (SEMS) product, prior to version 3.4.2 MP1, may be susceptible to a denial of service (DoS) exploit. A DoS attack is a type of attack whereby the perpetrator attempts to make a particular machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a specific host within a network.
How severe is CVE-2018-5243?: CVE-2018-5243 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 none, integrity none, and availability high.
Is CVE-2018-5243 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-5243?: CVE-2018-5243 affects Symantec Encryption Management Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-5243?: 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-2018-5243 published?: CVE-2018-5243 was published on 2018-08-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:symantec:encryption_management_server:*:*:*:*:*:*:*:*

More vulnerabilities in Symantec Encryption Management Server

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CVE-2015-8149 — High (CVSS 7.5): The LDAP service in Symantec Encryption Management Server (SEMS) 3.3.2 before MP12 allows remote attackers to cause a…
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