How severe is CVE-2021-20099?

CVE-2021-20099 has a CVSS 3.x base score of 6.7, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-20099 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20099?

CVE-2021-20099 affects Tenable Nessus. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20099?

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

When was CVE-2021-20099 published?

CVE-2021-20099 was published on 2021-06-28 and last updated on 2026-06-17.

CVE-2021-20099

CVE-2021-20099 is a medium-severity vulnerability in Tenable Nessus with a CVSS 3.x base score of 6.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 6.7)
CVSS v2: 4.6
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Tenable Nessus
Published: 2021-06-28
Last modified: 2026-06-17

Description

Nessus Agent 8.2.4 and earlier for Windows were found to contain multiple local privilege escalation vulnerabilities which could allow an authenticated, local administrator to run specific Windows executables as the Nessus host. This is different than CVE-2021-20100.

Frequently asked questions

What is CVE-2021-20099?: Nessus Agent 8.2.4 and earlier for Windows were found to contain multiple local privilege escalation vulnerabilities which could allow an authenticated, local administrator to run specific Windows executables as the Nessus host. This is different than CVE-2021-20100.
How severe is CVE-2021-20099?: CVE-2021-20099 has a CVSS 3.x base score of 6.7, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-20099 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20099?: CVE-2021-20099 affects Tenable Nessus. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20099?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20099 published?: CVE-2021-20099 was published on 2021-06-28 and last updated on 2026-06-17.

References

https://www.tenable.com/security/tns-2021-12

Affected products (1)

cpe:2.3:a:tenable:nessus:*:*:*:*:*:*:*:*

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