Securin’s (previously CSW) Expert Discovers a Zero-Day Vulnerability in Tenable’s Nessus Scanner

How Could This Vulnerability Be Exploited?

Proof of Concept

1. Install Nessus Essentials or Professional, log on to the scanner, and create a Nessus policy with credentials using any Credential Type (in our case, Windows).

2. Run a credentialed scan using the created Nessus policy.

3. Create a process dump file of the process ‘nessusd’ from the Windows Task Manager.

Figure 3: Created the Process Dump of the “nessusd” Process

4. Parse the dump file (.DMP) using the Sysinternals tool “Strings” and extract information by extracting lines with the string “Login configurations.”

Figure 4: Parsing the DMP File Using Strings and Extracting Credentials

5. The Nessus policy’s Windows Domain Credentials have been retrieved in cleartext and viewed using a text editor application.

Figure 5: The Nessus Policy-Stored Windows Credentials Retrieved in Cleartext

Impact of the Vulnerability

1. An attacker can retrieve stored credentials in Nessus Policies in cleartext from the “nessusd” process.
2. An attacker can potentially compromise corresponding assets, internal domains, and networks with the retrieved credentials.
3. With disclosed credentials, an attacker can potentially compromise an organization’s associated assets and networks, leading to infiltration and breach.

Timeline

1. April 25, 2022: Securin’s expert discovered CVE-2022-28291 in Nessus Professional version 10.1.1 (#61)
2. May 02, 2022: Reported to Tenable’s team
3. June 02, 2022: Tenable proposed a potential fix in Nessus 10.4 or in a later release
4. August 04, 2022: Tenable deemed the reported vulnerability as an acceptable risk
5. August 31, 2022: Tenable performed additional reviews and acknowledged there would be no fix for this issue
6. September 01, 2022: Tenable agreed to raise a CVE for this submission