Oh boy here goes. This is the first post of many, in which I will touch the topic of bypassing Firewalls. This being the Introduction of this series, I will focus on setting the topic up, providing explanations and all that stuff.
Some of the resources I will provide are screenshots from chats I took in the Telegram Messenger. I’ve had many and very lenghty converstaions with a some very awesome individuals over the past few months. These people all have a need to bypass Firewalls on a daily basis. I was also lurking around in subreddits and forums where people are discussing that topic.
First things first, WHY would anyone need to bypass a firewall? Firewalls are mostly perceived as a security measure. They are installed on your endpoint machine or in the network, or… well both, and they make sure no malware reaches your PC. And while this is not exactly wrong, that isn’t completely true either.
Because my english sucks, here is the first definition from Wikipedia:
In computing, a firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.
That’s pretty accurate so far, although I would personally cross out the word ‘security’. Because Firewalls are also commonly used to censor and surveil the users that sit behind it. The most famous example for that is probably the Great Firewall of China (GFW). It’s the wet dream of any totalitarist leader in the modern world, and a very powerful tool in shielding away reality from citizens for the purpose of propaganda. But I might write more about the GFW another day.
I am also in contact with a couple of folks from Iran, a country which has a form of internet censorship which is similar to China. The freedom of chinese and iranian people is actively limited by their oppresive governments, bypassing the censorship machine means liberation!
See, I am not in china, neither am I chinese. I am very privileged to live in a country where I mostly have free access to any kind of information I desire. Therefore, the GFW is nothing I personally have to fear. But there are more reasons so even someone like me might have genuine interest in bypassing firewalls. Even though my freedom is not limited by my government.
Less dramatic reasons for bypassing Firewalls
A classical example why one wold want to bypass a firewall, are free WiFi Hotspots. Germany's mobile network is trash. And expensive too. So when I can, I use open WiFi Hotspots. Now these aren’t often the safest option out there, and some of them are straight up nefarious. I was in a Subway the other day, the one where you get sandwiches, and after connecting to the WiFi my browser was barfing all sorts of SSL error messages out. This network actually deployed their own Certificate, which would break the encryption of any HTTPS site if used. They could straight up log my internet activity. We are in 2019, and I am sure that violates the GDPR and probably other laws, but whatever. Who cares about data protection laws right?
I have no idea why they do that. As far as I am concerned it may just be a misconfiguration. Maybe.
One argument now could be, just to not connect to such a network in the first place. And sure, I could. Fair point. But I can also use a VPN and continue using free WiFi while eating my damn fastfood.
Another thing happenend at my school. It deploys a network filter, like many schools do. What sucks is that they block web.de, amongst many other sites. Web.de is a webmail provider that also delivers news. These news are very clickbaity and generally low quality, and I guess that is why the school has blocked it. (Although it was listed under ‘pornography’ which was odd.) Now as luck would strike me, I had to reset a password. Mail sent to my web.de Account. Well, I was able to get to my mails, because I could bypass the restriction that was set by the firewall. But usually I would have not been able to.
These two examples show security and usability concerns respectively. Avoiding the firewall means avoiding sniffing and restrictions.
I was also chatting with a guy from Cuba. Take a look at what he wrote to me:
Now it gets comical. That guy is a SysAdmin. One would think using SSH is useful for such a person.
Okay and… how?
After I have (hopefully) made clear why there are many reasons to bypass Firewalls, what remains is the question how to bypass them. And this, dear reader, will be in the next blog post.
In the meantime, anyone who is interested in that topic can write me a PM on telegram, and when there is a genuine interest, come and join this Telegram group and chat with me and others about this topic.