ModSecurity supplies an array of request and response filtering rules and other security features to the Apache HTTP Server. ModSecurity is an open source web application layer firewall.

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15
votes
5answers
12k views

mod_security block requests by http-host header

The last few days I noticed some servers being hammered with unknown requests. Most of them are like the following: 60.246.*.* - - [03/Jan/2015:20:59:16 +0200] "GET ...
10
votes
2answers
12k views

mod_security - PCRE limits exceeded

Just about on every request I am getting the following error: Rule execution error - PCRE limits exceeded (-8): (null). After a bunch of googling the only solutions seem to be a) Add the following ...
8
votes
1answer
4k views

What are PCRE limits?

In ModSecurity there are PCRE limits exceeded errors. I know I can fix this by setting rules such as: SecPcreMatchLimit 150000 SecPcreMatchLimitRecursion 150000 But, what are these rules actually ...
7
votes
2answers
10k views

Disable modsecurity For a Specific Directory

How do you disable modsecurity for just a specific directory. I'm getting errors in phpMyAdmin that are caused by modsecurity tripping based on rules. I have the following files set up: # ...
6
votes
2answers
356 views

Good free guide for mod_security?

I have looked at the official sites documentation, and it is a little tough to find starting points. Is there a free comprehensive guide that is easy to understand for someone that has never dealt ...
5
votes
2answers
3k views

Why does modsecurity require Content-Length in POST requests?

I have a RESTful web service that accepts a POST request to a resource without an entity body, e.g. an empty POST request. The default modsecurity configuration requires that all POST requests have a ...
5
votes
1answer
646 views

ModSecurity on Apache (Debian Wheezy), Authentication logging

I am new to ModSecurity, it works great on the server, but I would like to control the way it logs things. For example as I am troubleshooting my website in order to whitelist or correct php coding ...
5
votes
2answers
167 views

How to include ModSecurity request final action in the Apache access.log

I'm currently using ModSecurity 2.7 and Apache 2.4.7 on Ubuntu Trusty. I would like to use Apache's LogFormat and CustomLog directives so that I can include a field indicating whether ModSecurity ...
4
votes
2answers
250 views

Why bother reverse proxying applications if you aren't using mod_security or TMG/UAG?

Common wisdom is that internal applications that live inside of the trusted network, such as Exchange, should be reverse proxies whenever they are exposed to the Internet. Microsoft recommends using ...
4
votes
2answers
7k views

mod_security not actually blocking requests despite rule trigger & returning 403

I've pulled my finger out and installed mod_security to protect our WHMCS installation (a PHP based billing system) from some of the more obvious SQL injection attacks to try and minimise our ...
4
votes
2answers
12k views

How do I find out if mod_security is installed on my apache server?

How can I find out if mod_security is installed on my apache server? I would also like to learn its version. I'm having some upload issues and I tried to disable mod_security using .htaccess. But ...
4
votes
1answer
186 views

SecAuditLogParts not working: mod_security keeps logging response body

I have set SecAuditLogParts in modsecurity.conf to just log ABFH, but the modsecurity audit log keeps logging -E- part (response body) which makes the audit log too big. What can I do to disable ...
4
votes
1answer
1k views

modsecurity: block IP address that visited 404 pages more than 10 times in a minute

We're using mod_security and we have currently issues with some bots. I would like to block IP Address that visited 404 pages more than 10 times in a minute. How can this be done? How can I poll the ...
4
votes
1answer
1k views

How to get mod_security to log all POST data?

I currently have a CentOS system that is successfully logging relevant mod_security actions to the audit log file. The following is my configuration: <IfModule mod_security2.c> SecRuleEngine ...
4
votes
3answers
5k views

Why does mod_security require an ACCEPT HTTP header field?

After some debugging, I found that the core ruleset of mod_security blocks requests that don't have the (optional!) ACCEPT header field. This is what I find in the logs: ModSecurity: Warning. ...
3
votes
1answer
3k views

Enable Mod_Security for only one website

Is there a way to dis-able mod-security for all websites? except one? i have more than 500 websites hosted, only want to turn it on for one website, which is having attacks on it.
3
votes
2answers
6k views

ModSecurity block specific string in request

I want a ModSecurity rule, which block the access to any url or any Body request Post/Get, if it contains a specific string. For example i want to block this string : "km0ae9gr6m" I have this rule ...
3
votes
2answers
9k views

mod_unique_id: unable to find IPv4 address of FQDN despite setting etc/hosts and Apache ServerName

I'm trying to get mod_security and hit the very common hostname error of [alert] (EAI 2)Name or service not known: mod_unique_id: unable to find IPv4 address of "computername.domain.com" This ...
3
votes
3answers
660 views

Block traffic behind AWS ELB

My web servers are behind ELB, I want to block traffic from some specific user agent which is a DDOS attack. Apache always see ip address of ELB as an end user so I tried below attempts: Blocking IP ...
3
votes
2answers
3k views

mod_security 960015 blocks Google and other good bots

mod_security rule 960015 keeps catching Google and other good bots. I have the following in the vhost to prevent good bots from being caught: SecRule REQUEST_HEADERS:User-Agent "Mail.ru" log,allow ...
3
votes
1answer
77 views

Modifying Apache configuration via a Web Interface

I would like to create a website on my server, which runs Apache2, to allow a user to fill in a form containing a desired subdomain name to be created on the server. For example, a user could go to ...
3
votes
1answer
1k views

Looking for a good web penetration testing client

I'm implementing mod_security on an apache server. In order to test the effectiveness of the protection, I am looking for a client that can generate a set of predefined malicious HTTP requests. I will ...
3
votes
1answer
1k views

mod_security ruleset for Joomla! admin

I run several hosting servers and recently I have experienced a lot of bruteforce attacks against joomla-based websites. Attackers seem to try a bruteforce against administrator/index.php page. I ...
3
votes
1answer
102 views

ModSecurity on IIS: Single threaded?

I installed ModSecurity on a web server running IIS 8.5, and noticed the response time has increased 15 times (0.15 ms/request vs. 2.2 ms/request), even with SecEngine set to off. It seems that IIS is ...
3
votes
1answer
738 views

What do the audit log records for ModSecurity actually mean?

We have ModSecurity setup to log to modsec_audit.log for Apache2. Today we have had 2259 entries created in this log with a referrer of: Mozilla/5.0 (compatible; bingbot/2.0; ...
3
votes
2answers
411 views

Mod_security Logging

Im trying to run mod_security as standalone service with nginx as reverse proxy everything works fine except logging. Mod_security logs reverse proxys ip addres instead of clients ip address. I would ...
2
votes
2answers
2k views

Necesity of ModSecurity if Apache is behind Nginx

I have my Apache installed behind Nginx. So every request that comes in is first handeled by Nginx. If there is dynamic content needed the request is send to Apache which listens on port 8080. Pretty ...
2
votes
3answers
3k views

mod_security: another rule with same ID

I have installed httpd 2.2.15 on CentOS 6.5 (minimal installation with no cPanel) with modsecurity 2.8. When I am starting httpd I am getting this error: Starting httpd: Syntax error on line 23 of ...
2
votes
1answer
799 views

Do I really need mod_security?

I'm doing a clean install of my server and I'm looking for some advice on whether or not I actually need the Apache mod_security module. I consider myself to be a bit security paranoid when it comes ...
2
votes
3answers
4k views

Test whether mod_security is actually working

I'm running this on my staging server for the first time and I think I did everything correctly. I can see entries in modsec_audit.log when I run nikto2 against it, but for the life of me I can't ...
2
votes
2answers
2k views

modsecurity apache mod-security.conf missing [closed]

Greetings Serverfaultians. I'm not a server guy as you can see from my noob score of 1 point. But maybe those more versed can help me. I'm using Ubuntu v13.10 32-bit Server and Apache2 v2.4.6 and I'm ...
2
votes
2answers
171 views

How to use Modsec rules to certain page?

i want to block proxy(x-forwarded) ip certain page(wp-comments-post.php) using Apache Mod_security. my current mod_security rule: SecRule REQUEST_HEADERS_NAMES "^x-forwarded-for" ...
2
votes
1answer
1k views

what is the impact of increasing the SecResponseBodyLimit from default value (512k) to (5M)?

I installed the mod_security version 2.5.13 with apache2 and I'm facing problem with SecResponseBodyLimit: ( ModSecurity: Output filter: Response body too large (over limit of 524288, total not ...
2
votes
2answers
1k views

mod_security IP collection key not being set correctly

I'm using an IP collection in a load balanced setup, I therefor want mod_security to act on the x-forwarded for header instead of the REMOTE_ADDR. Here is my rule: SecAction ...
2
votes
1answer
684 views

why use apache's LoadFile?

Installing mod_security, the instructions direct us to add: LoadFile /usr/lib/libxml2.so LoadFile /usr/lib/liblua5.1.so to httpd.conf. I'm wondering why they might prefer LoadFile to linking with ...
2
votes
1answer
3k views

Why Is ModSecurity Unable to Access the Data Directory?

Update I think we've solved this; the problem appears to have been a result of the /modsec_storage directory having an incorrect value for its SELinux context type. However, we're still not sure, ...
2
votes
0answers
26 views

Any versions of ModSecurity that works with recent versions of Nginx?

I'm building Nginx and ModSecurity together in order to use the OWASP- Core Rule Set Project. According to the modsecurity download page, the latest version of modsecurity (2.9.1) is not stable when ...
2
votes
1answer
86 views

ModSecurity rule to not scan URI

I am having difficulty creating a new mod security 2.5 rule. My deployment: Apache server, Setup as a reverse proxy. (so the apache webserver __does not_ host the website. Instead, I proxy the ...
2
votes
0answers
127 views

ModSecurity phase not working?

I have installed modsecurity (2.8). So I made my first rule to block a referrer spam with the following: SecRule REQUEST_HEADERS:Referer "buttons\-for\-website\.com" ...
2
votes
1answer
958 views

Mod Security ctl:ruleEngine=Off Whitelist Fails in Phase 1 [closed]

Background info : cPanel server with atomicorp ruleset, plus our own custom rules and whitelists in separate .conf files - Apache 2.2, modsec 2.8 Whitelist rule: SecRule REMOTE_ADDR ...
2
votes
0answers
527 views

How to filter POST data with mod_security when type is text/xml?

I'm trying to craft a rule which would match certain regex in POST requests. Rule I have so far looks like; SecRule REQUEST_FILENAME "form.php" \ "id:'12345',chain,deny,status:406,log,msg:'foobar ...
2
votes
0answers
239 views

Nginx and dynamic X-Forwarded-For blocklist

I am running Nginx behind a proxy. I am getting visitors' real IP addresses through X-Forwarded-For HTTP request header. I'd like to block individual IPs based on a dynamic block list, up to 10000+ ...
2
votes
0answers
78 views

.htaccess ignored two layers deep on only some hosting plans [closed]

I have one .htaccess file doing this: RewriteRule ^system(.*)$ /system/app/$1 [QSA,L] ...and then underneath /system/app, I have another .htaccess file doing this: RewriteCond %{REQUEST_FILENAME} ...
2
votes
0answers
183 views

Custom collections with mod_security

I would like to create a mod_security collection that is based on something other than the user's IP, Session ID, or username. Specifically, based on the REQUEST_URI. However, mod_security indicates ...
2
votes
1answer
2k views

Where I can find ModSecurity Rules for Specific Applications

Where I can find ModSecurity Rules for Specific Applications specially joomla, wordpress, mambo ?
1
vote
3answers
3k views

How to drop all requests using mod_security

I have an apache2 server with several sites enabled on it, including the default one (000default). The default server is catching lots of spammy requests that are doing nothing but consume bandwidth ...
1
vote
2answers
839 views

Blocking bad bots

I found this script and was wondering if this is just overkill and even worth using? Is it better for me to just use mod_security? # Generated using http://solidshellsecurity.com services # Begin ...
1
vote
2answers
4k views

mod_security configuration issue: Error parsing actions: Unknown action: ver

I am trying to install / configure mod-sec using this tutorial, which uses the OWASP ModSecurity Core Rule Set. However when I go to restart apache, I get the following error: Syntax error on line 53 ...
1
vote
2answers
859 views

mod_security never tells what the problem is

Normally I would just pester my provider to disable the rule. And while he certainly deserves pestering, I've done that way too often already for the low service price. (Like always this is about a ...
1
vote
2answers
8k views

how I can know which version of mod security that I had on the server? and how I can update it? [closed]

I'm using cpanel (11.25 Stable 46156) with mod security installed. How can I know the version of mod security that installed in the server? How can I update mod security manually or make it update ...