How severe is CVE-2021-20135?

CVE-2021-20135 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-2021-20135 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20135?

CVE-2021-20135 affects Tenable Nessus. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20135?

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

When was CVE-2021-20135 published?

CVE-2021-20135 was published on 2021-11-03 and last updated on 2026-06-17.

CVE-2021-20135

CVE-2021-20135 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% (22nd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Tenable Nessus
Published: 2021-11-03
Last modified: 2026-06-17

Description

Nessus versions 8.15.2 and earlier were found to contain a local privilege escalation vulnerability which could allow an authenticated, local administrator to run specific executables on the Nessus Agent host. Tenable has included a fix for this issue in Nessus 10.0.0. The installation files can be obtained from the Tenable Downloads Portal (https://www.tenable.com/downloads/nessus).

Frequently asked questions

What is CVE-2021-20135?: Nessus versions 8.15.2 and earlier were found to contain a local privilege escalation vulnerability which could allow an authenticated, local administrator to run specific executables on the Nessus Agent host. Tenable has included a fix for this issue in Nessus 10.0.0. The installation files can be obtained from the Tenable Downloads Portal (https://www.tenable.com/downloads/nessus).
How severe is CVE-2021-20135?: CVE-2021-20135 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-2021-20135 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20135?: CVE-2021-20135 affects Tenable Nessus. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20135?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20135 published?: CVE-2021-20135 was published on 2021-11-03 and last updated on 2026-06-17.

References

https://www.tenable.com/security/tns-2021-18

Affected products (1)

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

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