The vulnerability that allows the attacker to see the passwords being transmitted in clear text is the lack of encryption on the VPN links. Encryption is a process of transforming data into an unreadable form, so that only authorized parties can access it. VPN (Virtual Private Network) is a technology that creates a secure tunnel between two or more devices over a public network, such as the Internet. VPN links should be encrypted to prevent eavesdropping, tampering, or spoofing of the data that passes through them. If the VPN links are not encrypted, an attacker can use a packet sniffer to intercept and read the data, including the passwords, that are sent over the network. This is called a sniffing attack, and it can lead to credential theft, identity spoofing, or data manipulation. Therefore, VPN links should always use strong encryption protocols, such as IPsec or SSL/TLS, to protect the confidentiality and integrity of the data. References :=
Some possible references are:
Implementing and Operating Cisco Security Core Technologies (SCOR) v1.0 - Cisco: This is the official course page for the SCOR 350-701 exam, which covers the topics of implementing and operating Cisco security core technologies. It provides the course objectives, outline, duration, and prerequisites. It also offers various learning options, such as instructor-led training, e-learning, and practice exams.
SCOR 350-701 Official Cert Guide - Cisco Press: This is the official study guide for the SCOR 350-701 exam, written by Omar Santos, a principal engineer at Cisco’s Security Research and Operations group. It covers all the exam topics in depth, with explanations, examples, exercises, and practice questions. It also includes a companion website with online resources, such as videos, quizzes, flashcards, and more.
Cleartext submission of password - PortSwigger: This is a web security article that explains the vulnerability of transmitting passwords over unencrypted connections, and how to exploit it using Burp Suite, a web application testing tool. It also provides some remediation advice, such as using HTTPS and HSTS to enforce encryption.
What Are Sniffing Attacks, and How Can You Protect Yourself? - EC-Council: This is a blog post that describes what sniffing attacks are, how they work, and what are the common types and tools of sniffing attacks. It also provides some tips on how to prevent or detect sniffing attacks, such as using encryption, VPN, firewall, IDS, and anti-sniffing software.
OWASP Application Security FAQ | OWASP Foundation: This is a frequently asked questions page about application security, maintained by the Open Web Application Security Project (OWASP), a non-profit organization that promotes web security awareness and best practices. It covers various topics, such as authentication, authorization, session management, input validation, output encoding, cryptography, error handling, logging, and more.
