| Oracle® Fusion Middleware Oracle HTTP Serverの管理 12c (12.1.2) E48019-03 |
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mod_securityは、Oracle HTTP Serverに対する侵入攻撃を検出および防止するために使用できる、オープンソース・モジュールです。たとえば、mod_securityルールを指定して、すべての受信リクエストをスクリーニングし、ルールで指定された条件に一致するリクエストを拒否することができます。mod_securityモジュール(バージョン2.7.2)とその前提条件は、mod_security2.soという共有オブジェクトとして、ORACLE_HOME/ohs/modulesディレクトリ内のOracle HTTP Serverインストールに含まれています。
このバージョンのOHSは、mod_security (バージョン2.7.2)のディレクティブ、変数、アクション、フェーズおよび関数のみをサポートしています。このモジュールをより新しいバージョンに置き換えると、これらはサポートされなくなります。
この付録では、loadModule文を含む、mod_security.confファイルの使用可能な例(例E–1)について説明します。
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注意: 次のことに注意してください。
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mod_securityの詳細は、次のmod_securityドキュメント・サイトを参照してください。
http://www.modsecurity.org/documentation/
この章の構成は、次のとおりです。
Oracle HTTP Serverの実行時にmod_securityモジュールを使用できるようにするには、mod_security.confが次の行で開始されていることを確認します。
#Load module
LoadModule security2_module "${PRODUCT_HOME}/modules/mod_security2.so"
例F-1のmod_security.confの例を参照してください。
mod_securityを構成する際には、Oracle HTTP Server構成ファイルで特定のディレクティブを指定する必要があります。IfModuleコンテナ内のhttpd.confファイルで直接ディレクティブを指定できます。別の方法として、別個のmod_security.confファイルにmod_securityディレクティブを指定し、Includeディレクティブを使用してhttpd.confにその.confファイルを含めることもできます。
デフォルトではmod_security.confは存在しないので、可能であれば例F-1のテンプレートを使用して、mod_security.confを作成する必要があります。テキスト・エディタにサンプルをコピーして貼り付け、ファイル全体を読んで、使用しているシステム用に編集します。次に、それを自身のmod_security.confとして保存し、httpd.confに含めます。この付録の手順に従ってmod_security.confを実装する場合は、LoadModuleディレクティブを使用してmod_security2.soを実行環境にロードします。
例F-1 mod_security.confの例
#Load module
LoadModule security2_module "${PRODUCT_HOME}/modules/mod_security2.so"
# -- 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 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 "text/xml" "id:'200000',phase:1,t:none,t:lowercase,pass,nolog,ctl:requestBodyProcessor=XML"
# 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
# Store up to 128 KB of request body data in memory. When the multipart
# parser reachers this limit, it will start using your hard disk for
# storage. That is slow, but unavoidable.
#
SecRequestBodyInMemoryLimit 131072
# What do 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
# 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:'200001', 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:'200002',phase:2,t:none,log,deny,status:44, \
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?
#
SecRule MULTIPART_UNMATCHED_BOUNDARY "!@eq 0" \
"id:'200003',phase:2,t:none,log,deny,status:44,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:'200004',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 "${ORACLE_INSTANCE}/servers/${COMPONENT_NAME}/logs/modsec_audit.log"
# Specify the path for concurrent audit logging.
SecAuditLogStorageDir "${ORACLE_INSTANCE}/servers/${COMPONENT_NAME}/logs"
#Simple test
SecRule ARGS "\.\./" "t:normalisePathWin,id:99999,severity:4,msg:'Drive Access'"
# -- 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.
#
#SecUnicodeCodePage 20127
#SecUnicodeMapFile unicode.mapping
