Someone please please tell me this is not correct. Reading this link, seem like one can de-crypted https traffic via fiddler. Does it mean if I am doing online banking via https, someone who can intercept this traffic can read my account and pin key information?
Fiddler requires you to install a special SSL root certificate for it to be able to listen to HTTPS traffic. Once you install it, Fiddler can install itself as a proxy (middleman), faking that it's every HTTPS site on the Internet. In short, yes, it can listen to everything over HTTPS, but you need to manually install the certificate on your machine first to allow it.
In theory, any root certificate you install on your machine - Fiddler or not - will allow the person generating it to impersonate any Internet site, so never do it without considering the ramifications.
In SSL terms, what Fiddler does is that it installs itself as a certificate authority on your machine. When you access a HTTPS site for which it is acting as middleman, it quickly generates a certificate claiming to be the site in question. Since the root certificate is on your machine, it will trust Fiddler's certificate and happily let it decrypt everything.
Fiddler will act as a Man in the Middle, using its own SSL certificate, and thus triggering browser warnings. If you are suitably deterred by those warnings, nobody will snoop on your online banking sessions.
For more on how this works, you can read about public-key cryptography.
You have to accept the ssl certificate issued by fiddler but yes you can monitor ssl traffic with fiddler. If you dig a bit deeper there are more sophisticated tools for MITM attacks like: https://www.owasp.org/index.php/Category:OWASP_WebScarab_Project
Related
Recently I found myself working with Guzzle while making requests to another server to post and fetch some data, in some cases, tokens. But I was getting certificate invalid error and I even tried to get a new .pem certificate, but Guzzle was still not accepting and kept throwing that error. So finally, I did what the "Internet" said:
$guzzleClient = new Client([
'verify' => false
]);
Now although this solution works, I am not sure how insecure it can get. Do I need to worry? If yes, in what scenarios?
well this is a big problem if you are for example
having login system on the request you are sending using guzzle
having payment/checkout on the request
basically any sensitive data being passed to the other server
because when you pass data without SSL certificate then your requests might get caught by malicious programs like
BurbSuite / WireShark , cain and abel / EtterCap
as these programs are Sniffing programs and anyone can get a version from the internet as they are open sourced and every thing going without SSL can be intercepted by the hacker using the tools mentioned above and the hacker can look to the entire request in plaintext! so its highly recommended to use SSL connection when passing sensitive data
Worth Mentioning : now a days even SSL isn't very secure because hackers can remove it using SSLStrip tool but believe me SSL will make it much harder for them to get to your request because if they used it your website sometimes will make non-completed requests and it will notify the user that the network isn't secure this will make it very hard for the hacker to get the user's data,
TLS/SSL in common configurations is meant to give you three things:
confidentiality - no third party is able to read the messages sent and received,
integrity - no third party is able to modify the messages sent and received,
server authentication - you know who are you talking to.
What you do with setting verify to false is disabling the certificate verification. It immediately disables the server authentication feature and enables loosing confidentiality and integrity too when facing an active attacker that has access to your data stream.
How is that?
First of all TLS/SSL relieas on Public Key Infrastructure. Without going into too much details: you hold on your machine a set of certificates of so called Certification Authorities (CA) whom you trust. When you open a new communication to a service, you get the services certificates and in the process of verification you validate amongst other things if the certificate belongs to a CA you trust. If yes, then the communication may proceed. If no, then the communication channel is closed.
Attack patterns
Disabling certificate verification allows for Man-in-the-Middle (MitM) attacks than can easily be performed in your local network (e.g. via ARP poisoning attacks), in the local network of the service you are calling or in the network between. As we usually do not trust the network completely, we tend to verify.
Imagine me performing an attack on you. I have performed ARP poisoning, now I can see all your traffic. It's encrypted, isn't it? Well, not obviously. The TCP handshake and TLS handshake you believe you have performed with the target service - you have performed with me. I have presented you not the certificate of the target service, as I am unable to fake it, but my own. But you did not validate it to reject it. I have opened a connection between me and the target service on your behalf too so I can look into the decrypted traffic, modify if necessary and reply to you to make you believe everything is ok.
First of all - all your secrets are belong to me. Second of all - I am able to perform attacks on both you and the target service (which might have been secured by authentication mechanisms, but now is not).
How to fix this?
In XXI century there should be little reason to disable TLS verification anywhere. Configuring it to work properly might be a pain though, even more when you are doing it for the first time. From my experience the most common issues in the micro service world are:
the target certificate is self-signed,
you are missing a CA root certificate in your trust store,
the microservice does provide his certificate, but does not provide an intermediate CA certificate.
It's hard to guess what your issue is. We would need to dig deeper.
While the other answers points out some really good point about how important SSL/TLS is, your connection is still encrypted and the remote endpoint you're using has https:// in it as well. So you're not entirely disabling SSL when you set verify to false if I'm not mistken. It's just less secure since that you're not verifying the certificate of the remote server if they are signed by a Certificate Authority (CA) using the CA bundle.
Do you need to worry?
If this is something on your production, ideally you'd want things to be secure and configured correctly, so yes.
By not verifying the certificate, like Marek Puchalski mentioned, there's possibility of the server might not be the one you think it is and allows mitm (man in the middle) attack as well. More about mitm here, and peer verification here.
Why is it happening & how do you fix it?
Most common issue is misconfigured server, especially PHP configuration. You can fix your PHP configuration following this guide, where you'll be using adding the CA root certificates bundle to your configuration. Alternatively you can add this to Guzzle.
Another common issue is, the remote server is using a self-signed certificate. Even if you configured your CA bundle in your trustedstore, this certificate can't be trusted since it's not signed by a trusted CA. So the server needs to configure a SSL certificated signed by a CA. If that's not possible, you can manually trust this CA root, however this comes with some security concerns as well.
Hope this helped :)
In my work computer, Firefox always gives me the "sec_error_unknown_issuer" error. This happens only on all HTTPS sites.
I have browsed Mozilla's support forums and understood that this is most probably caused by a software that performs an HTTPS scanning. The software presents its "fake" certificates to Firefox and hence, Firefox says that it does not know the issuer of these certificates.
However, I don't know which software is performing the HTTPS scanning and presenting its "fake" certificates to Firefox.
Is there a way to determine which software is performing the HTTPS scanning so that I will be able to add its certificates to Firefox and hence, be able to use the Firefox properly?
In my work computer,...which software is performing the HTTPS scanning
This is probably legal SSL interception done by a firewall in your company. If you want to know the exact software used for scanning ask your local network administrator.
... so that I will be able to add its certificates to Firefox and hence, be able to use the Firefox properly?
If you look at what certificates your server sends you have a look at the certificate details in the browser, especially at the chain certificates. But to make sure that what you get is really the companies certificate used for SSL interception and not some malicious man-in-the-middle attack you should verify your finding with your network administrator. And I'm pretty sure that if they do legal SSL interception they also help you do add the certificate to your browser - at least as long you are allowed to install alternative browsers to your computer and/or your own computer to connect to the companies network.
By a sniffer (Fiddler), I can check out the stream sent through my PC to network. Surprisingly, I found when I log in google's account (https), the password is sent in a clear text, e.g.
POST https://accounts.google.com/ServiceLoginAuth HTTP/1.1
...
Email=abc#gmail.com&**Passwd=12345678**
My question is: why the password is passed without encryption even with a https protocol?
HTTPS encrypts the entire request and response.
However, you're telling Fiddler to decrypt using an untrusted root certificate.
In other words, you're MITMing yourself, and telling the browser to ignore the untrusted certificate.
No, the password is not sent without encryption to Google as clear text. Google is using SSL, don't worry. But you installed Fiddler on your PC. When you did so, Fiddler registered a specific root level certificate on your computer and is able to decrypt the traffic between your web browser and the internet. By installing Fiddler, you explicitly granted this application the possibility to decrypt the traffic. So, yeah, anyone able to get administrator access to a PC is able to install a root level certificate to this PC and consequently is able to decrypt all traffic between this PC and the internet. What did you expect? How do you think trojans work?
But any man-in-the-middle attacks won't work because they won't be able to decrypt the SSL traffic between your web browser and the internet.
This question already has answers here:
What is point of SSL if fiddler 2 can decrypt all calls over HTTPS?
(3 answers)
Closed 7 years ago.
I have just discovered that Fiddler can decrypt HTTPS traffic.
For instance, I deployed a website on localhost using HTTPS. When inspecting the data packets in Fiddler, I was able to view all the information since it has an option to decrypt it.
My question is, why make use of HTTPS when Fiddler can easily decrypt it?
Fiddler performs a MITM technique.
To make it work, you need to trust its Certificate:
http://www.fiddler2.com/fiddler/help/httpsdecryption.asp
If you don't, it won't decrypt anything...
how can Fiddler2 debug HTTPS traffic?
A: Fiddler2 relies on a "man-in-the-middle" approach to HTTPS
interception. To your web browser, Fiddler2 claims to be the secure
web server, and to the web server, Fiddler2 mimics the web browser.
In order to pretend to be the web server, Fiddler2 dynamically
generates a HTTPS certificate.
Fiddler's certificate is not trusted by your web browser (since
Fiddler is not a Trusted Root Certification authority), and hence
while Fiddler2 is intercepting your traffic, you'll see a HTTPS error
message in your browser [...]
In order to decrypt HTTPS traffic you must first install the Fiddler's root certificate in to your "trusted/root certificates" list. Fiddler's root certificate is NOT a Root certificate which by default comes with your Operating System. The OS will usually warn you when you're trying to install this.
In doing so, you explicitly begin to trust any certificate signed by Fiddler's root certificate. When you now make a https request, Fiddler will perform a Man in the middle attack with you.
Suppose you make a request in the form https://google.com. Fiddler will now act as the actual Google server and will create a dummy certificate for Google.com and sign it using Fiddler's Root certificate. You will receive this dummy certificate which has been signed by Fiddler. This certificate will pass your device's validation since Fiddler's Root certificate is now in your trusted certificates. Now, your device will start communicating with Fiddler through a secure HTTPS connection. Fiddler will relay your messages to Google.com and back to you. Of course Fiddler will able to decrypt them.
It is to note that the traffic from Fiddler to Google will occur through a second Secure https channel.
Therefore, not to worry about the security provided by https.
I'm running mitmdump (from mitmproxy) on my Macbook Pro, and I'm connecting to the proxy through my Windows desktop PC.
However, Chrome (running on the PC) refuses to connect to so many sites because of the invalid certificates which mitmproxy provides.
Chrome throws the error: ERR::NET_CERT_AUTHORITY_INVALID
Here's what mitmdump shows:
But why? What's wrong with mitmproxy's certificates, why can't it just send back google's as if nothing happened?
I'd like to know how I can fix this and make (force) my desktop PC to connect to any website through my Macbook's mitmproxy.
Answering this question for people who may find this important now. To get the proxy working, you have to add the certificate as trusted in your browser.
For windows follow this: https://www.nullalo.com/en/chrome-how-to-install-self-signed-ssl-certificates/2/
For linux follow this: https://dev.to/suntong/using-squid-to-proxy-ssl-sites-nj3
For Mac-os follow this: https://www.andrewconnell.com/blog/updated-creating-and-trusting-self-signed-certs-on-macos-and-chrome/#add-certificate-to-trusted-root-authority
There are some additional details in the above links; tldr; import the certificate in your chrome://settings url and add the certificate as trusted. That shall do.
This will make your browser trust your self-signed certificate(mitm auto generated certificates too.)
The default certificates of mitmproxy is at ~/.mitmproxy/ directory.
Per the Getting Started page of the docs you add the CA by going to http://mitm.it while mitmproxy is running and selecting the operating system that you are using. This should solve your problem and will allow https sites to work with mitmproxy.
This is the expected behavior.
mitmproxy performes a Man-In-The-Middle attack to https connections by providing on-the-fly generated fake certificates to the client while it keeps communicating to the server over fully encrypted connection using the real certificates.
This way the communication between client and proxy can be decrypted. But the client has to actively approve using those fake certificates.
If that wasn't the case then SSL would be broken - which it isn't.
The whole story is very well explained here:
http://docs.mitmproxy.org/en/stable/howmitmproxy.html