Today's Deep-Dive: BunkerWeb

Okay, so every organization, anyone really running a web service, an application,

maybe an API,

you face this huge immediate problem, right? How do you build that digital shield?

Something

strong enough to keep out sophisticated attacks without needing a whole army of

security experts

just to keep it running. And maybe even more critically, how do you actually trust

that shield?

That's what we're tackling today. We're doing a deep dive into BunkerWeb. It's an

open source,

next-gen web application firewall or WAIFO. And look, this isn't just about

blocking bad traffic.

It's really about challenging that whole security industry model, the one where you're

kind of

forced to trust these opaque proprietary, well, black boxes. Yeah. Our mission

today is to show

you how total transparency and the secure by default idea really changes the game,

even if,

maybe especially if you're kind of new to network security. But first, a huge thank

you to the

supporter of the Steep Dive, SafeServer. SafeServer handles software hosting and

they support you in

your digital transformation journey. You can find out more, learn how they can help

with your

infrastructure at www.safeserver.de. Okay, let's unpack this then. We're talking

about a WAF,

a web application firewall. When you think WAF, where exactly does BunkerWeb fit

into that picture?

Well, think of it like the ultimate checkpoint, really. Away is a specialized

security system,

and you place it strategically in front of your web services. Its whole job is to

inspect every

single piece of incoming traffic and, crucially, block malicious requests before

they can even

get near your application code. This is, I mean, absolutely fundamental if you want

to ensure the

confidentiality, integrity, and availability of your data, you know, the CIA triad.

And a key

point you mentioned is that BunkerWeb functions specifically as a reverse proxy.

Can you maybe

quickly explain the operational benefit there? Why have all traffic flow through BunkerWeb

first

instead of just letting it hit the application directly? Right. The big win is

centralization

and, honestly, simplicity. Because all that traffic hits the proxy first, BunkerWeb

becomes your

single secure entry point. And this allows it to seamlessly handle really crucial

tasks, like

managing all the incoming HTTP and HTTPS traffic, enforcing security policies

uniformly across

everything behind it, and even automating things that are normally a huge pain,

like getting and

renewing HTTPS or to think it's automatically using what's encrypted. You basically

manage security

from one spot. That simplicity sounds absolutely critical. Okay, so what specific

dangers are we

really talking about here? If I put the shield up, what's it actually fighting off

day to day?

It's designed to neutralize the most common, the most prevalent web threats you see

out there. So

naturally, that includes all the stuff detailed in the infamous OWASP top 10,

things like SQL

injection attempts, cross-site scripting, the usual suspects. But it goes beyond

just application

level flaws. It's actively blocking malicious bots, and bots are a huge percentage

of unwelcome

traffic these days. And it also helps mitigate large-scale distributed denial of

service attacks,

DDoS attacks, the ones designed just to overwhelm your servers and take you offline.

Yeah, that definitely makes web security seem much more approachable. But like you

said earlier,

complexity isn't just about the threats themselves, it's also about trust. If a

security

tool is handling literally all your incoming traffic, acting as that gatekeeper,

how do you

know it's not the weak link? How do you know it's not introducing vulnerabilities

or, I don't know,

silently leaking data? And that question, I think, leads us right into Bunkerweb's

core philosophy.

Exactly. And what's really fascinating here is their absolute commitment to open

security.

They distribute under the AGPL v3 free license, and they very openly contrast this

approach

with what they call security through obscurity, which, let's be honest, is how most

wave vendors

operate. They sell you an opaque black box. You just have to trust their marketing,

trust their

promise that it's secure inside. Bunkerweb demands the opposite. Okay, but doesn't

that

seem a bit counterintuitive? You know, opening up your security mechanisms for

anyone to look at,

doesn't that just give attackers a roadmap, increase the chance they'll find

vulnerabilities?

That's a fair question, and it's one that comes up a lot with open source.

But the reality, or at least the philosophy here, is that the benefits of

transparency

dramatically outweigh that perceived risk. The whole approach is built around

collective strength.

Think about the core pillars. Transparency means the source code is right there.

Anyone can audit it anytime. This directly enables auditability. Users, security

researchers,

independent third parties, they can all verify the security claims. It's not just

taking someone's

word for it. Right. That verification step is huge for building confidence. If

trust isn't

just a promise, but something you can actually check, that's powerful. Absolutely.

And this leads

directly to sovereignty. You, the user, maintain control and ownership over your

data and your

security setup. You're not locked into relying solely on a vendor's black box. And

finally,

everyone benefits from the active community. You get improvements, bug fixes, new

ideas,

all coming from global collaboration. It makes the tool stronger over time.

They have that quote that really sums it up. Do not choose the shadows anymore,

discover the light.

It's quite evocative. And that mindset leads directly to their core promise, secure

by default.

But hang on a second, that sounds great. Secure by default. But doesn't setting

strong default

policies carry a big risk of just breaking things? Like if I deploy this in front

of some older,

maybe slightly quirky legacy application, how do I know those defaults won't just

block legitimate

users right out of the gate? Yeah, that's the classic security

trade-off, isn't it? Every deployment faces that balance. The point of secure by

default here

isn't to be unbreakable from the start, but to ensure you start from a known,

protected state,

rather than starting with zero protection and having to build everything up.

The system enforces a baseline security policy immediately. Things like applying

basic HTTP

security headers, maybe some TLS hardening, it gets you to a decent starting point.

From there, yes, you absolutely use the logs and the UI to tune those policies. You

might need to

loosen a rule for a specific application or maybe tighten one, but it shifts the

burden. You're not

building protection from scratch. You're adjusting existing protection. It's a

different mindset.

Okay. That makes more sense. So let's look at the actual tools, the features that

provide that

protection. Beyond the philosophy, what specific capabilities does BunkerWeb offer

right out of the

box? Well, we've already touched on the automated HTTPS support with Let's Encrypt,

and the

foundational security headers. Those are table stakes, really. But fundamentally,

it includes

the integrated mod security WAF. And critically, it's paired with the OWASP core

rule set. That's

a massive, constantly updated library of rules specifically designed to detect

common known attack

patterns. It's sort of the industry standard rule set. Plus, you get mechanisms for

limiting

connections and requests per client, which is important to stop, say, one abusive

user or bot

from hogging all your server resources. I also saw on the feature list something

about blocking

known bad IPs using external blacklists and DNSBL. We sometimes throw these acronyms

around. DNSBL,

what exactly does that do for the average person trying to protect their

application?

Right. DNSBL stands for Domain Name System Blacklist. Think of it like a shared

global

database of known troublemakers online. These are IP addresses that have already

been caught sending

spam, distributing malware, launching attacks elsewhere on the internet. By

integrating DNSBL

support, BunkWhip essentially checks every visitor's IP address against these

massive

lists of known bad actors. If there's a match, it just turns them away immediately

before they even

get a chance to try anything malicious on your server. It's very effective

proactive defense.

That sounds really practical. But the feature that really caught my eye, especially

with all

the talk about sophisticated web scraping and malicious automation, is the anti-bot

feature.

How does BunkerWeb actually stop those bots without just annoying or blocking

legitimate users?

Oh yeah, the anti-bot stuff is clever. It introduces a challenge layer. So if BunkerWeb

detects

suspicious behavior, maybe traffic patterns that look very robotic, or requests

coming too fast,

it requires the client, the browser, to solve a task to prove it's likely human.

This could be

something relatively simple, like asking the browser to set a cookie or execute a

little bit

of JavaScript. Or you can configure it to escalate to more familiar human

verification systems,

like a standard CAPTCHA image challenge. Or using third-party services like AceCAPTCHA

or Google's ReCAPTCHA. If the client fails the challenge, or simply can't execute

it like many

simple bots can't run JavaScript, they get blocked. Hmm, I'm fascinated by that.

Let's say I enable

AceCAPTCHA. What actually happens under the hood if a bot fails that challenge? Is

it just blocked

for that one request, or does its IP address get penalized somehow? Like, how

quickly does it adapt?

It generally depends on how you've configured the policy. But typically, failing

the challenge

results in an immediate denial of service for that specific request or session.

And often, yes, it triggers temporary blacklisting to integrated IP reputation

modules. So that IP

might be blocked from accessing the site entirely for, say, the next 15 minutes or

an hour, depending

on your settings. The system is highly configurable. You get to determine the

sensitivity, how quickly

it triggers a challenge, and the duration of any subsequent ban. It lets you fine-tune

that balance

between user experience and aggressive bot mitigation. That adaptability really

speaks to

the architecture, doesn't it? I know it's built on what they call the six pillars.

Two of those

that stand out are agnostic and modular. What do those mean in practice? Right. Agnostic

basically

means the solution doesn't really care where you deploy it. It's designed to slide

easily into

various environments. You can run it on a standard Linux server, inside Docker

containers, manage it

with Kubernetes or Swarm, or even deploy it within cloud platforms like Microsoft

Azure. It's flexible

and modular is all about extendability. It's a pretty robust plugin system. This is

crucial because,

let's face it, modern threats are diverse and sometimes you need a specialized tool

for a

specific job. The core WAIFF can't do everything. Okay. Can you give us a specific

example? Like,

how would a plugin extend the security in a way that, say, the base NGINX or mod

security

wouldn't handle by default? Sure. A classic example is file uploads. Uploads are a

huge

vector for malware getting onto your server. So, you could install the ClamAV

plugin for BunkerWeb.

Now, when a user tries to upload a file, BunkerWeb intercepts it before it hits

your application,

passes it to the ClamAV scanner, and if ClamAV detects malware signatures,

BunkerWeb just denies the request immediately. The malicious file never even

reaches your backend.

Another simple but really powerful example is integrations for notifications. You

can set up

plugins for Discord or Slack webhooks. This means if BunkerWeb blocks a serious

attack or detects

some other critical security event, it can instantly send a notification right into

your

operations team's chat channel. That dramatically cuts down your response time.

Okay, all this

configuration, plugins, rule sets. It sounds like it could get pretty intense

pretty quickly.

Which brings us to the user experience. I mean, security settings can be incredibly

dense, so

ease of use has got to be paramount, right? Especially for someone who isn't, you

know,

living in the command line all day. Absolutely. And the awesome web UI, their words,

but it is

pretty good, is arguably the biggest differentiator for ease of use. You really don't

need to be a

Linux command line wizard or memorize complex NGINX configuration syntax to manage

BunkerWeb

effectively. You can handle most things, managing your settings, installing or

removing plugins,

viewing logs, seeing which attacks were blocked all through a standard graphical

web interface,

makes it much more accessible. And configuration itself is mostly handled through

simple settings

or variables. You're not typically editing raw text files. Instead, you might set a

variable in

the UI, like use the end about CAPTCHA or enable the NSPL true. It abstracts away a

lot of the

complexity. That level of abstraction sounds vital, especially for beginners trying

to get started.

But okay, if BunkerWeb is built on NGINX, which is known for being super reliable

and fast,

why does it need this separate brain component, the scheduler? What specific

management tasks

does that part handle that NGINX doesn't? Ah, good question. That's where the

orchestration

and the dynamic management happen. NGINX is fantastic at serving requests very,

very quickly,

but it primarily works off a static configuration file. You load the config, NGINX

runs with it.

The scheduler acts as the central control plane. It manages the database where all

your dynamic

settings, your plugin configurations, your custom rules are stored. It handles

background jobs,

like periodically checking for and renewing Let's Encrypt certificates, updating

blacklist feeds,

applying temporary IP bans based on rule violations. And crucially, whenever you

make a

change through the web UI, like enabling a plugin or adjusting a security setting,

the scheduler takes

that change, updates its internal state, and then generates the new optimized NGINX

configuration

file and tells NGINX to reload it gracefully. It essentially automates that whole

secure management

layer that plain NGINX lacks on its own, provides the intelligence on top. Okay,

yeah, that explains

the sort of automagic functionality much better. Makes sense. Finally, let's talk

about scale for a

second. What if I'm not just protecting one website? What if I'm managing a more

complex

environment, maybe with dozens of separate web applications or services? How does BunkerWeb

handle that efficiently? That's exactly what multi-site mode is designed for. By

default,

a standard BunkerWeb instance protects one upstream application. But once you

enable multi-site

mode, a single BunkerWeb instance can act as the reverse proxy in Double F for

multiple different

backend applications, multiple virtual hosts, essentially. And each of the

protected applications

can have its own customized set of security rules, its own specific plugin

configurations on settings.

This offers tremendous efficiency. You don't need to spin up a separate BunkerWeb

instance

for every single app. It really helps reduce the infrastructure footprint required

to protect

a larger, more sprawling environment. And as we kind of noted earlier, while this

open source

version is free and sounds really robust, definitely enough for hobbyists, testing,

maybe even some mid-sized operations. There are also professional options available,

right? Like

Shield, Fortress, Sentinel, for organizations that need more, perhaps, enterprise

support

or managed cloud offerings. Exactly. The core protection engine, the open source

heart, remains

the same across the board. That's key. The professional tiers typically add things

like

dedicated technical support contracts, service level agreements, SLAs, perhaps

advanced reporting

features, or fully managed service models where they handle the deployment and

operation for you.

But the fundamental open source core provides that robust, auditable protection

right from the start

for anyone to use. Okay, so let's try to synthesize all this. BunkerWeb seems to

deliver really robust

and importantly transparent web security. It does this by combining that wave

capability with a

reverse proxy structure. It aims to simplify these complex security challenges

using a

user-friendly UI and, crucially, that secure by default mantra, all powered by open

source

collaboration. So if you out there are scaling your web services or maybe going

through a broader

digital transformation, this open source approach seems to offer a lot of

flexibility and perhaps

most importantly verifiable trust. And that really brings us to a final thought,

something for you,

the listener, to consider based on all this. Given the choice between open security,

where the code

is visible, auditable by anyone, you can see exactly how it works, and the

alternative, security

to obscurity, where your critical defense mechanism is essentially a black box that

you just have to

take on faith, which approach truly offers you genuine long-term confidence when it

comes to

protecting your most valuable digital assets and data. That is a vital question for

anyone managing

any kind of internet presence today, a really important consideration. And with

that, we'll

wrap up this deep dive into BunkerWeb. Thank you again to our supporter for making

this possible.

SafeServer, they're there to help you with hosting and your digital transformation.

You can find out more at www.safeserver.de. Thanks for joining us and we'll catch

next time for the next deep dive.

next time for the next deep dive.