How severe is CVE-2021-4038?

CVE-2021-4038 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-4038 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-4038?

CVE-2021-4038 affects Mcafee Network Security Manager. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-4038?

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

When was CVE-2021-4038 published?

CVE-2021-4038 was published on 2021-12-09 and last updated on 2026-06-17.

CVE-2021-4038

CVE-2021-4038 is a medium-severity vulnerability in Mcafee Network Security Manager with a CVSS 3.x base score of 4.8. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 4.8)
CVSS v2: 3.5
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Mcafee Network Security Manager
Published: 2021-12-09
Last modified: 2026-06-17

Description

Cross Site Scripting (XSS) vulnerability in McAfee Network Security Manager (NSM) prior to 10.1 Minor 7 allows a remote authenticated administrator to embed a XSS in the administrator interface via specially crafted custom rules containing HTML. NSM did not correctly sanitize custom rule content in all scenarios.

Frequently asked questions

What is CVE-2021-4038?: Cross Site Scripting (XSS) vulnerability in McAfee Network Security Manager (NSM) prior to 10.1 Minor 7 allows a remote authenticated administrator to embed a XSS in the administrator interface via specially crafted custom rules containing HTML. NSM did not correctly sanitize custom rule content in all scenarios.
How severe is CVE-2021-4038?: CVE-2021-4038 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-4038 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-4038?: CVE-2021-4038 affects Mcafee Network Security Manager. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-4038?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-4038 published?: CVE-2021-4038 was published on 2021-12-09 and last updated on 2026-06-17.

References

https://kc.mcafee.com/corporate/index?page=content&id=SB10375

Affected products (1)

cpe:2.3:a:mcafee:network_security_manager:*:*:*:*:*:*:*:*

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