I forgot the username and password for my nessus setup, so here are the steps to troubleshoot the issues:

# This command will show the existing usernames on your machine
sudo /opt/nessus/sbin/nessuscli lsuser
# changing the passweord for a particular username
sudo /opt/nessus/sbin/nessuscli chpasswd 0xdf_fak3r

Give a new password and you are good to go, navigate to the portal of nessus -> nessus

Scanning with nessus:

  1. Start the nessus service using the command sudo /bin/systemctl start nessusd.service , then navigate to https://kali:8834
  2. After login, click on the new scan button: nessus_1
  3. Select advance scan from the options: nessus_2
  4. Fill out this basic details first , and setup the target Ip nessus_3
  5. You can customize other settings also, then hit save and Launch. nessus_4

Scan analysis:

nessus_5 List of security vulnerabilities.

  1. Click on any of the vulns: nessus_6
  2. As shown in the preceding screenshot, Nessus also provides the Common Vulnerability Scoring System (CVSS) base score, which is based on a rating from 0-10, where 10 is the most critical and requires immediate attention.
Important

Cybersecurity professionals within the industry use the CVSS calculator at https://www.first.org/cvss/ to determine the score of vulnerabilities within their systems, networks, and organizations. This calculation helps experts determine the risk factors when determining a severity rating.

nessus_7 3. We can further export the results of the scan into different formats.