Awesome-WAF

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.”

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)

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.

Contents:

• Introduction
  • How WAFs Work
  • Operation Modes
• Testing Methodology
  • Where To Look
  • Detection Techniques
• WAF Fingerprints
• Evasion Techniques
  • Fuzzing/Bruteforcing
  • Regex Reversing
  • Obfuscation/Encoding
  • Browser Bugs
  • HTTP Header Spoofing
  • Google Dorks Approach
• Known Bypasses
• Awesome Tooling
  • Fingerprinting
  • Testing
  • Evasion
• Blogs & Writeups
• Video Presentations
• Research Presentations & Papers
  • Research Papers
  • Presentation Slides
• Licensing & Credits

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 <script>*</script> 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 <script>alert()</script> 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 or Scapy.

11. Side Channel Attacks - Examine the timing behaviour of the request and response content.

    Tip: More details can be found in a blogpost here.

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.

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 [email protected]. 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.
Sec

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