Prepare modsecurity module

This commit is contained in:
Dryusdan 2024-01-02 15:49:59 +01:00
parent 9e6d85bb0b
commit b538eaf777
5 changed files with 329 additions and 0 deletions

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@ -49,6 +49,20 @@
- install
- reconfigure
- name: Install Nginx and dependencies
apt:
pkg: "{{item}}"
state: latest
update_cache: yes
with_items:
- libmodsecurity3
- libnginx-mod-http-modsecurity
- modsecurity-crs
when: nginx_modsecurity is defined
tags:
- install
- reconfigure
- name: Creates directory
file:
path: /etc/nginx/ssl/private
@ -154,6 +168,22 @@
- install
- reconfigure
- name: Add modsecs templated configuration
template:
src: "{{ item.src }}"
dest: "{{ item.dest }}"
mode: 0640
owner: root
group: root
loop:
- { 'src': 'modsecurity.conf.j2', 'dest': '/etc/nginx/modsecurity.conf' }
- { 'src': 'modsecurity_includes.conf.j2', 'dest': '/etc/nginx/modsecurity_includes.conf' }
- { 'src': 'owasp-crs.load.j2', 'dest': '/usr/share/modsecurity-crs/owasp-crs.load' }
when: nginx_modsecurity is defined
tags:
- install
- reconfigure
- name: "Add errors html file"
copy:
src: "{{ item.src }}"

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@ -0,0 +1,285 @@
# -- Rule engine initialization ----------------------------------------------
# Enable ModSecurity, attaching it to every transaction. Use detection
# only to start with, because that minimises the chances of post-installation
# disruption.
#
SecRuleEngine {{ nginx_modsecurity_secruleengine | default('DetectionOnly') }}
# -- Request body handling ---------------------------------------------------
# Allow ModSecurity to access request bodies. If you don't, ModSecurity
# won't be able to see any POST parameters, which opens a large security
# hole for attackers to exploit.
#
SecRequestBodyAccess On
# Enable XML request body parser.
# Initiate XML Processor in case of xml content-type
#
SecRule REQUEST_HEADERS:Content-Type "^(?:application(?:/soap\+|/)|text/)xml" \
"id:'200000',phase:1,t:none,t:lowercase,pass,nolog,ctl:requestBodyProcessor=XML"
# Enable JSON request body parser.
# Initiate JSON Processor in case of JSON content-type; change accordingly
# if your application does not use 'application/json'
#
SecRule REQUEST_HEADERS:Content-Type "^application/json" \
"id:'200001',phase:1,t:none,t:lowercase,pass,nolog,ctl:requestBodyProcessor=JSON"
# Sample rule to enable JSON request body parser for more subtypes.
# Uncomment or adapt this rule if you want to engage the JSON
# Processor for "+json" subtypes
#
#SecRule REQUEST_HEADERS:Content-Type "^application/[a-z0-9.-]+[+]json" \
# "id:'200006',phase:1,t:none,t:lowercase,pass,nolog,ctl:requestBodyProcessor=JSON"
# Maximum request body size we will accept for buffering. If you support
# file uploads then the value given on the first line has to be as large
# as the largest file you are willing to accept. The second value refers
# to the size of data, with files excluded. You want to keep that value as
# low as practical.
#
SecRequestBodyLimit 13107200
SecRequestBodyNoFilesLimit 131072
# What to do if the request body size is above our configured limit.
# Keep in mind that this setting will automatically be set to ProcessPartial
# when SecRuleEngine is set to DetectionOnly mode in order to minimize
# disruptions when initially deploying ModSecurity.
#
SecRequestBodyLimitAction Reject
# Maximum parsing depth allowed for JSON objects. You want to keep this
# value as low as practical.
#
SecRequestBodyJsonDepthLimit 512
# Maximum number of args allowed per request. You want to keep this
# value as low as practical. The value should match that in rule 200007.
SecArgumentsLimit 1000
# If SecArgumentsLimit has been set, you probably want to reject any
# request body that has only been partly parsed. The value used in this
# rule should match what was used with SecArgumentsLimit
SecRule &ARGS "@ge 1000" \
"id:'200007', phase:2,t:none,log,deny,status:400,msg:'Failed to fully parse request body due to large argument count',severity:2"
# Verify that we've correctly processed the request body.
# As a rule of thumb, when failing to process a request body
# you should reject the request (when deployed in blocking mode)
# or log a high-severity alert (when deployed in detection-only mode).
#
SecRule REQBODY_ERROR "!@eq 0" \
"id:'200002', phase:2,t:none,log,deny,status:400,msg:'Failed to parse request body.',logdata:'%{reqbody_error_msg}',severity:2"
# By default be strict with what we accept in the multipart/form-data
# request body. If the rule below proves to be too strict for your
# environment consider changing it to detection-only. You are encouraged
# _not_ to remove it altogether.
#
SecRule MULTIPART_STRICT_ERROR "!@eq 0" \
"id:'200003',phase:2,t:none,log,deny,status:400, \
msg:'Multipart request body failed strict validation: \
PE %{REQBODY_PROCESSOR_ERROR}, \
BQ %{MULTIPART_BOUNDARY_QUOTED}, \
BW %{MULTIPART_BOUNDARY_WHITESPACE}, \
DB %{MULTIPART_DATA_BEFORE}, \
DA %{MULTIPART_DATA_AFTER}, \
HF %{MULTIPART_HEADER_FOLDING}, \
LF %{MULTIPART_LF_LINE}, \
SM %{MULTIPART_MISSING_SEMICOLON}, \
IQ %{MULTIPART_INVALID_QUOTING}, \
IP %{MULTIPART_INVALID_PART}, \
IH %{MULTIPART_INVALID_HEADER_FOLDING}, \
FL %{MULTIPART_FILE_LIMIT_EXCEEDED}'"
# Did we see anything that might be a boundary?
#
# Here is a short description about the ModSecurity Multipart parser: the
# parser returns with value 0, if all "boundary-like" line matches with
# the boundary string which given in MIME header. In any other cases it returns
# with different value, eg. 1 or 2.
#
# The RFC 1341 descript the multipart content-type and its syntax must contains
# only three mandatory lines (above the content):
# * Content-Type: multipart/mixed; boundary=BOUNDARY_STRING
# * --BOUNDARY_STRING
# * --BOUNDARY_STRING--
#
# First line indicates, that this is a multipart content, second shows that
# here starts a part of the multipart content, third shows the end of content.
#
# If there are any other lines, which starts with "--", then it should be
# another boundary id - or not.
#
# After 3.0.3, there are two kinds of types of boundary errors: strict and permissive.
#
# If multipart content contains the three necessary lines with correct order, but
# there are one or more lines with "--", then parser returns with value 2 (non-zero).
#
# If some of the necessary lines (usually the start or end) misses, or the order
# is wrong, then parser returns with value 1 (also a non-zero).
#
# You can choose, which one is what you need. The example below contains the
# 'strict' mode, which means if there are any lines with start of "--", then
# ModSecurity blocked the content. But the next, commented example contains
# the 'permissive' mode, then you check only if the necessary lines exists in
# correct order. Whit this, you can enable to upload PEM files (eg "----BEGIN.."),
# or other text files, which contains eg. HTTP headers.
#
# The difference is only the operator - in strict mode (first) the content blocked
# in case of any non-zero value. In permissive mode (second, commented) the
# content blocked only if the value is explicit 1. If it 0 or 2, the content will
# allowed.
#
#
# See #1747 and #1924 for further information on the possible values for
# MULTIPART_UNMATCHED_BOUNDARY.
#
SecRule MULTIPART_UNMATCHED_BOUNDARY "@eq 1" \
"id:'200004',phase:2,t:none,log,deny,msg:'Multipart parser detected a possible unmatched boundary.'"
# PCRE Tuning
# We want to avoid a potential RegEx DoS condition
#
SecPcreMatchLimit 1000
SecPcreMatchLimitRecursion 1000
# Some internal errors will set flags in TX and we will need to look for these.
# All of these are prefixed with "MSC_". The following flags currently exist:
#
# MSC_PCRE_LIMITS_EXCEEDED: PCRE match limits were exceeded.
#
SecRule TX:/^MSC_/ "!@streq 0" \
"id:'200005',phase:2,t:none,deny,msg:'ModSecurity internal error flagged: %{MATCHED_VAR_NAME}'"
# -- Response body handling --------------------------------------------------
# Allow ModSecurity to access response bodies.
# You should have this directive enabled in order to identify errors
# and data leakage issues.
#
# Do keep in mind that enabling this directive does increases both
# memory consumption and response latency.
#
SecResponseBodyAccess On
# Which response MIME types do you want to inspect? You should adjust the
# configuration below to catch documents but avoid static files
# (e.g., images and archives).
#
SecResponseBodyMimeType text/plain text/html text/xml
# Buffer response bodies of up to 512 KB in length.
SecResponseBodyLimit 524288
# What happens when we encounter a response body larger than the configured
# limit? By default, we process what we have and let the rest through.
# That's somewhat less secure, but does not break any legitimate pages.
#
SecResponseBodyLimitAction ProcessPartial
# -- Filesystem configuration ------------------------------------------------
# The location where ModSecurity stores temporary files (for example, when
# it needs to handle a file upload that is larger than the configured limit).
#
# This default setting is chosen due to all systems have /tmp available however,
# this is less than ideal. It is recommended that you specify a location that's private.
#
SecTmpDir /tmp/
# The location where ModSecurity will keep its persistent data. This default setting
# is chosen due to all systems have /tmp available however, it
# too should be updated to a place that other users can't access.
#
SecDataDir /tmp/
# -- File uploads handling configuration -------------------------------------
# The location where ModSecurity stores intercepted uploaded files. This
# location must be private to ModSecurity. You don't want other users on
# the server to access the files, do you?
#
#SecUploadDir /opt/modsecurity/var/upload/
# By default, only keep the files that were determined to be unusual
# in some way (by an external inspection script). For this to work you
# will also need at least one file inspection rule.
#
#SecUploadKeepFiles RelevantOnly
# Uploaded files are by default created with permissions that do not allow
# any other user to access them. You may need to relax that if you want to
# interface ModSecurity to an external program (e.g., an anti-virus).
#
#SecUploadFileMode 0600
# -- Debug log configuration -------------------------------------------------
# The default debug log configuration is to duplicate the error, warning
# and notice messages from the error log.
#
#SecDebugLog /opt/modsecurity/var/log/debug.log
#SecDebugLogLevel 3
# -- Audit log configuration -------------------------------------------------
# Log the transactions that are marked by a rule, as well as those that
# trigger a server error (determined by a 5xx or 4xx, excluding 404,
# level response status codes).
#
SecAuditEngine RelevantOnly
SecAuditLogRelevantStatus "^(?:5|4(?!04))"
# Log everything we know about a transaction.
SecAuditLogParts ABIJDEFHZ
# Use a single file for logging. This is much easier to look at, but
# assumes that you will use the audit log only ocassionally.
#
SecAuditLogType Serial
SecAuditLog /var/log/nginx/modsec_audit.log
# Specify the path for concurrent audit logging.
#SecAuditLogStorageDir /opt/modsecurity/var/audit/
# -- Miscellaneous -----------------------------------------------------------
# Use the most commonly used application/x-www-form-urlencoded parameter
# separator. There's probably only one application somewhere that uses
# something else so don't expect to change this value.
#
SecArgumentSeparator &
# Settle on version 0 (zero) cookies, as that is what most applications
# use. Using an incorrect cookie version may open your installation to
# evasion attacks (against the rules that examine named cookies).
#
SecCookieFormat 0
# Specify your Unicode Code Point.
# This mapping is used by the t:urlDecodeUni transformation function
# to properly map encoded data to your language. Properly setting
# these directives helps to reduce false positives and negatives.
#
SecUnicodeMapFile unicode.mapping 20127
# Improve the quality of ModSecurity by sharing information about your
# current ModSecurity version and dependencies versions.
# The following information will be shared: ModSecurity version,
# Web Server version, APR version, PCRE version, Lua version, Libxml2
# version, Anonymous unique id for host.
SecStatusEngine On

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@ -0,0 +1,2 @@
include /etc/nginx/modsecurity.conf
include /usr/share/modsecurity-crs/owasp-crs.load

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@ -97,6 +97,10 @@ http {
# font/opentype
# image/svg+xml;
{% if nginx_modsecurity is defined %}
modsecurity on;
modsecurity_rules_file /etc/nginx/modsecurity_includes.conf;
{% endif %}
##
# Virtual Host Configs
##

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@ -0,0 +1,8 @@
##
## This file loads OWASP CRS's rules when the package is installed
## It is Included by libapache2-mod-security2
##
Include /etc/modsecurity/crs/crs-setup.conf
Include /etc/modsecurity/crs/REQUEST-900-EXCLUSION-RULES-BEFORE-CRS.conf
Include /usr/share/modsecurity-crs/rules/*.conf
Include /etc/modsecurity/crs/RESPONSE-999-EXCLUSION-RULES-AFTER-CRS.conf