Privilege escalation in Nessus Agent

1) Arbitrary file upload

EUVDB-ID: #VU54451

Risk: Low

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-20106

CWE-ID: CWE-434 - Unrestricted Upload of File with Dangerous Type

Exploit availability: No

Description

The vulnerability allows a remote user to compromise vulnerable system.

The vulnerability exists due to insufficient validation of file during file upload. A remote Nessus administrator user can upload a malicious file and escalate privileges on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Nessus Agent: 8.0.0 - 8.2.5

CPE2.3

• cpe:2.3:a:tenable_network_security:nessus_agent:8.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:tenable_network_security:nessus_agent:8.1.0:*:*:*:*:*:*:*
• cpe:2.3:a:tenable_network_security:nessus_agent:8.1.1:*:*:*:*:*:*:*

External links

https://www.tenable.com/security/tns-2021-13

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.