Question:

How can a proxy perform SSL inspection or man-in-the-middle attack without installing a certificate on the client device? >
> I have been using a public WiFi network at work for personal browsing on my own device, but I was not aware of the potential tracking by the ISP. I am concerned about the privacy and security of my online activity, especially if I visited any sensitive or inappropriate websites or links. My device does not have any certificates or profiles installed by the WiFi network, and neither did another device that I tested. Sometimes, I also get a warning that the network is not secure when I try to access an HTTPS website. In this situation, would the ISP be able to see the specific content of my HTTPS browsing, such as the subdomains, pages, or passwords? Or would they only see the main domain name, such as Reddit.com?

Answer:

How a proxy can spy on your HTTPS traffic without a certificate

HTTPS is a protocol that encrypts the communication between your browser and the web server, using SSL/TLS certificates to verify the identity of the server and prevent anyone from intercepting or tampering with your data. However, HTTPS is not foolproof, and there are ways that a proxy server can perform SSL inspection or man-in-the-middle attack without installing a certificate on your client device. In this article, we will explain how this can happen, what are the risks, and how you can protect yourself from such attacks.

How SSL inspection works

• Explain the concept of SSL inspection or HTTPS interception, which is the process of intercepting SSL/TLS encrypted internet communication between the client and server.
• Describe the role of the interception device or the ‘middlebox’, which sits in between the client and server, with all the traffic passing through it.
• Illustrate how the interceptor establishes an SSL connection with the web server, decrypts and examines the data, then creates another SSL connection with the client, using its own certificate.

How SSL inspection can be done without a certificate

• Discuss the scenarios where the interceptor does not need to install a certificate on the client device, such as:
• The client device already trusts the interceptor’s certificate, either because it is signed by a trusted certification authority, or because it is manually added by the user or the administrator.
• The client device ignores or bypasses the certificate validation, either because it is configured to do so, or because it is tricked by the interceptor using techniques such as DNS spoofing, HTTP redirection, or SSL stripping.
• Provide examples of legitimate and malicious uses of SSL inspection without a certificate, such as:
• Legitimate uses: antivirus scanning, web filtering, email filtering, etc. by network administrators or security software.
• Malicious uses: eavesdropping, data theft, phishing, malware injection, etc. by hackers, cybercriminals, or rogue ISPs.

What are the risks of SSL inspection without a certificate

• Analyze the potential threats and consequences of SSL inspection without a certificate, such as:
• Privacy violation: the interceptor can see the specific content of your HTTPS browsing, such as the subdomains, pages, passwords, personal information, etc.
• Security breach: the interceptor can modify the data in transit, such as injecting ads, malware, or malicious code, or redirecting you to fake or harmful websites.
• Certificate forgery: the interceptor can create fake, trusted certificates, using compromised or rogue certification authorities, and perform a man-in-the-middle attack to intercept and read/modify the traffic.

How

to protect yourself from SSL inspection without a certificate