Questions tagged [waf]

WAF stands for Web Application Layer Firewall. WAF is an application layer firewall that is meant to secure the back end web server by monitoring every HTTP request and response to and from the server.

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XSS with URL encoding

If a website URL gets encoded then is the website still vulnerable to XSS or no? For example, if I try <script>alert(1)</script> and the site URL encodes my payload to %3Cscript%3Ealert(1)...
Rifat Shommo's user avatar
3 votes
1 answer
2k views

How to filter https traffic in mod-security WAF?

I'm developing a WAF with good GUI and better log. And my base firewall is mod-security. It works well for http but I also want to work my WAF with https. Any suggestions?
Daniel Exar's user avatar
10 votes
3 answers
2k views

Evasion techiques for WAFs

Are there any documented techniques for evading Web application firewall for testing WAF rule configurations?
Ali Ahmad's user avatar
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7 votes
2 answers
10k views

Is SSL required for sites hosted behind WAF?

We have a website hosted behind WAF and we will be using HTTPS. The server already has a valid SSL. Do we need to install SSL on WAF servers also?
Arun's user avatar
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24 votes
1 answer
7k views

What is a Web Application Firewall?

What is a Web Application Firewall (WAF) and what are some of the things to look for in an effective one? Why would you deploy a WAF instead of just an IPS?
Sim's user avatar
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12 votes
2 answers
3k views

Secure HTTP Headers - where should be implemented, WAF or code level?

I have a REST API exposed to the Internet and another application with form-based authentication. These apps are behind a Web Application Firewall. Question is, where I should implement the below ...
Mathev's user avatar
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11 votes
4 answers
3k views

Why should I use whitelist on a WAF?

I was studying different WAFs, from open-source (such as ModSecurity and NAXSI) to commercial solutions (Imperva, Citrix, Fortinet, etc.). Many people state that having a whitelist-based WAF is far ...
Quentin Mollard's user avatar
4 votes
3 answers
2k views

Security implications of WAF revealing internal IP addresses

What are the security implications of a web app firewall/load balancer revealing internal IPs of the web sites behind it to the outside world? A specific example is with F5 products: They use a ...
nyxgeek's user avatar
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3 votes
3 answers
619 views

How useful is the default configuration of ModSecurity for a generic web application?

Scenario: ModSecurity with a "default" or "generic" configuration (like the one that might be provided by shared hosting providers, for example). Generic web application (custom, uncommon, or unknown)...
reed's user avatar
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1 vote
3 answers
12k views

ModSecurity errors related to REQUEST_METHOD HTTP/1.1 and GET

I asked my host to switch on the log file, and it have increasing a lot since then. Its have been increasing with 700 mb for the last week. It’s filled with error messages related to Mod Security. ...
Fredrik Johansson's user avatar