Security readout for executives and security teams
Plain-English summary
This vulnerability affects Nessus 8.13.2 and earlier. A Nessus administrator could upload a crafted file and potentially become administrator on the underlying Nessus host. The issue matters most where scanner administrators are numerous, third-party operated, or less tightly controlled.
Executive priority
Treat this as a controlled but meaningful remediation item. It is not evidenced as actively exploited in the supplied sources, but compromise of a vulnerability scanner host can expose sensitive network visibility and credentials.
Technical view
CVE-2021-20079 is a Nessus privilege escalation issue. The available record says an authenticated Nessus administrator can upload a specially crafted file that may lead to administrator privileges on the host running Nessus. The source bundle does not provide CVSS, CWE, exploit details, or fixed-version specifics.
Likely exposure
Exposure appears limited to Nessus deployments running version 8.13.2 or earlier, especially where Nessus administrator access is delegated broadly. The cited records do not identify other affected Tenable products or versions.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. Exploitation requires Nessus administrator access according to the CVE description, which reduces broad internet-driven risk but increases concern for insider, compromised-admin, or managed-service scenarios.
Researcher notes
Key missing evidence includes CVSS scoring, CWE mapping, exact fixed versions, and exploitation reports. Analysis should stay bounded to Nessus 8.13.2 and earlier unless Tenable or CVE sources identify additional affected products.
Mitigation direction
- Inventory Nessus servers and identify versions at or below 8.13.2.
- Review Tenable advisory TNS-2021-07 for vendor-approved upgrade or mitigation guidance.
- Restrict Nessus administrator roles to trusted personnel only.
- Review recent Nessus administrator activity for unexpected file uploads or configuration changes.
- Harden the Nessus host using least privilege and standard server controls.
Validation and detection
- Confirm every Nessus instance version through approved asset or scanner records.
- Verify no production instance remains on Nessus 8.13.2 or earlier.
- Review Nessus administrator account lists for unnecessary privileged users.
- Check host logs around Nessus administrative activity for unusual privilege changes.
- Document whether Tenable guidance has been applied to each affected server.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
Privilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-20079 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://www.tenable.com/security/tns-2021-07CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.