# ------------------------------------------------------------------------ # OWASP ModSecurity Core Rule Set ver.4.0.0-rc1 # Copyright (c) 2006-2020 Trustwave and contributors. All rights reserved. # Copyright (c) 2021-2022 Core Rule Set project. All rights reserved. # # The OWASP ModSecurity Core Rule Set is distributed under # Apache Software License (ASL) version 2 # Please see the enclosed LICENSE file for full details. # ------------------------------------------------------------------------ # # -= Paranoia Level 0 (empty) =- (apply unconditionally) # SecRule TX:DETECTION_PARANOIA_LEVEL "@lt 1" "id:941011,phase:1,pass,nolog,skipAfter:END-REQUEST-941-APPLICATION-ATTACK-XSS" SecRule TX:DETECTION_PARANOIA_LEVEL "@lt 1" "id:941012,phase:2,pass,nolog,skipAfter:END-REQUEST-941-APPLICATION-ATTACK-XSS" # # -= Paranoia Level 1 (default) =- (apply only when tx.detection_paranoia_level is sufficiently high: 1 or higher) # # In CRS v4.0, we have added REQUEST_FILENAME to the list of variables to # be checked for XSS to catch path-based XSS exploits such as: # /index.php/%3Csvg/onload=alert() # # However, the REQUEST_FILENAME is always populated (while ARGS etc. are # only set on some requests) and we found that always checking the # REQUEST_FILENAME has a significant performance impact. # Therefore, we are disabling the REQUEST_FILENAME XSS checks when the # REQUEST_FILENAME is clearly not containing special characters necessary # for a successful XSS. # # Some bona-fide REQUEST_FILENAMEs will still contain special characters # and will be checked by the rules, but it will be a much lower amount, # and that is a trade-off we are willing to make. # # So, we check for XSS in REQUEST_FILENAME only if it contains # other characters than alphanumeric characters, hyphens, underscores etc. # typically found in filenames and paths: # # - ascii 20 (whitespace) # - ascii 45-47 (- . /) # - ascii 48-57 (0-9) # - ascii 65-90 (A-Z) # - ascii 95 (underscore) # - ascii 97-122 (a-z) # # If just these characters are present, we remove REQUEST_FILENAME from the target # list of all the 941xxx rules starting 941100. # # Please note that it would be preferable to start without REQUEST_FILENAME in the # target list and to add it on a case to case base, but the rule language does not # support this feature at runtime. # SecRule REQUEST_FILENAME "!@validateByteRange 20, 45-47, 48-57, 65-90, 95, 97-122" \ "id:941010,\ phase:1,\ pass,\ t:none,\ nolog,\ ctl:ruleRemoveTargetById=941100-941999;REQUEST_FILENAME" # # -=[ Libinjection - XSS Detection ]=- # # Ref: https://github.com/client9/libinjection # Ref: https://speakerdeck.com/ngalbreath/libinjection-from-sqli-to-xss # # -=[ Targets ]=- # # 941100: PL1 : REQUEST_COOKIES|!REQUEST_COOKIES:/__utm/| # REQUEST_COOKIES_NAMES|REQUEST_HEADERS:User-Agent| # ARGS_NAMES|ARGS|XML:/* # # 941101: PL2 : REQUEST_FILENAME|REQUEST_HEADERS:Referer # SecRule REQUEST_COOKIES|!REQUEST_COOKIES:/__utm/|REQUEST_COOKIES_NAMES|REQUEST_HEADERS:User-Agent|ARGS_NAMES|ARGS|XML:/* "@detectXSS" \ "id:941100,\ phase:2,\ block,\ t:none,t:utf8toUnicode,t:urlDecodeUni,t:htmlEntityDecode,t:jsDecode,t:cssDecode,t:removeNulls,\ msg:'XSS Attack Detected via libinjection',\ logdata:'Matched Data: XSS data found within %{MATCHED_VAR_NAME}: %{MATCHED_VAR}',\ tag:'application-multi',\ tag:'language-multi',\ tag:'platform-multi',\ tag:'attack-xss',\ tag:'paranoia-level/1',\ tag:'OWASP_CRS',\ tag:'capec/1000/152/242',\ ver:'OWASP_CRS/4.0.0-rc1',\ severity:'CRITICAL',\ setvar:'tx.xss_score=+%{tx.critical_anomaly_score}',\ setvar:'tx.inbound_anomaly_score_pl1=+%{tx.critical_anomaly_score}'" # # -=[ XSS Filters - Category 1 ]=- # http://xssplayground.net23.net/xssfilter.html # script tag based XSS vectors, e.g., # SecRule REQUEST_COOKIES|!REQUEST_COOKIES:/__utm/|REQUEST_COOKIES_NAMES|REQUEST_FILENAME|REQUEST_HEADERS:User-Agent|REQUEST_HEADERS:Referer|ARGS_NAMES|ARGS|XML:/* "@rx (?i)]*>[\s\S]*?" \ "id:941110,\ phase:2,\ block,\ capture,\ t:none,t:utf8toUnicode,t:urlDecodeUni,t:htmlEntityDecode,t:jsDecode,t:cssDecode,t:removeNulls,\ msg:'XSS Filter - Category 1: Script Tag Vector',\ logdata:'Matched Data: %{TX.0} found within %{MATCHED_VAR_NAME}: %{MATCHED_VAR}',\ tag:'application-multi',\ tag:'language-multi',\ tag:'platform-multi',\ tag:'attack-xss',\ tag:'paranoia-level/1',\ tag:'OWASP_CRS',\ tag:'capec/1000/152/242',\ ver:'OWASP_CRS/4.0.0-rc1',\ severity:'CRITICAL',\ setvar:'tx.xss_score=+%{tx.critical_anomaly_score}',\ setvar:'tx.inbound_anomaly_score_pl1=+%{tx.critical_anomaly_score}'" # # -=[ XSS Filters - Category 3 ]=- # # Regular expression generated from regex-assembly/941130.ra. # To update the regular expression run the following shell script # (consult https://coreruleset.org/docs/development/regex_assembly/ for details): # crs-toolchain regex update 941130 # SecRule REQUEST_COOKIES|!REQUEST_COOKIES:/__utm/|REQUEST_COOKIES_NAMES|REQUEST_HEADERS:User-Agent|ARGS_NAMES|ARGS|REQUEST_FILENAME|XML:/* "@rx (?i).(?:\b(?:x(?:link:href|html|mlns)|data:text/html|formaction|pattern\b.*?=)|!ENTITY[\s\v]+(?:%[\s\v]+)?[^\s\v]+[\s\v]+(?:SYSTEM|PUBLIC)|@import|;base64)\b" \ "id:941130,\ phase:2,\ block,\ capture,\ t:none,t:utf8toUnicode,t:urlDecodeUni,t:htmlEntityDecode,t:jsDecode,t:cssDecode,t:removeNulls,\ msg:'XSS Filter - Category 3: Attribute Vector',\ logdata:'Matched Data: %{TX.0} found within %{MATCHED_VAR_NAME}: %{MATCHED_VAR}',\ tag:'application-multi',\ tag:'language-multi',\ tag:'platform-multi',\ tag:'attack-xss',\ tag:'paranoia-level/1',\ tag:'OWASP_CRS',\ tag:'capec/1000/152/242',\ ver:'OWASP_CRS/4.0.0-rc1',\ severity:'CRITICAL',\ setvar:'tx.xss_score=+%{tx.critical_anomaly_score}',\ setvar:'tx.inbound_anomaly_score_pl1=+%{tx.critical_anomaly_score}'" # # -=[ XSS Filters - Category 4 ]=- # XSS vectors making use of javascript uri and tags, e.g.,

# https://portswigger.net/web-security/cross-site-scripting/cheat-sheet#css-expressions-ie7 # https://portswigger.net/web-security/cross-site-scripting/cheat-sheet#behaviors-for-older-modes-of-ie # examples: https://regex101.com/r/FFEpsh/1 # SecRule REQUEST_COOKIES|!REQUEST_COOKIES:/__utm/|REQUEST_COOKIES_NAMES|REQUEST_HEADERS:User-Agent|REQUEST_HEADERS:Referer|ARGS_NAMES|ARGS|REQUEST_FILENAME|XML:/* "@rx (?i)[a-z]+=(?:[^:=]+:.+;)*?[^:=]+:url\(javascript" \ "id:941140,\ phase:2,\ block,\ capture,\ t:none,t:utf8toUnicode,t:urlDecodeUni,t:htmlEntityDecode,t:jsDecode,t:cssDecode,t:removeNulls,t:removeWhitespace,\ msg:'XSS Filter - Category 4: Javascript URI Vector',\ logdata:'Matched Data: %{TX.0} found within %{MATCHED_VAR_NAME}: %{MATCHED_VAR}',\ tag:'application-multi',\ tag:'language-multi',\ tag:'platform-multi',\ tag:'attack-xss',\ tag:'paranoia-level/1',\ tag:'OWASP_CRS',\ tag:'capec/1000/152/242',\ ver:'OWASP_CRS/4.0.0-rc1',\ severity:'CRITICAL',\ setvar:'tx.xss_score=+%{tx.critical_anomaly_score}',\ setvar:'tx.inbound_anomaly_score_pl1=+%{tx.critical_anomaly_score}'" # # -=[ NoScript XSS Filters ]=- # Ref: http://noscript.net/ # # [NoScript InjectionChecker] HTML injection # # Regular expression generated from regex-assembly/941160.ra. # To update the regular expression run the following shell script # (consult https://coreruleset.org/docs/development/regex_assembly/ for details): # crs-toolchain regex update 941160 # SecRule REQUEST_COOKIES|!REQUEST_COOKIES:/__utm/|REQUEST_COOKIES_NAMES|REQUEST_HEADERS:User-Agent|REQUEST_HEADERS:Referer|ARGS_NAMES|ARGS|REQUEST_FILENAME|XML:/* "@rx (?i)<[^0-9<>A-Z_a-z]*(?:[^\s\v\"'<>]*:)?[^0-9<>A-Z_a-z]*[^0-9A-Z_a-z]*?(?:s[^0-9A-Z_a-z]*?(?:c[^0-9A-Z_a-z]*?r[^0-9A-Z_a-z]*?i[^0-9A-Z_a-z]*?p[^0-9A-Z_a-z]*?t|t[^0-9A-Z_a-z]*?y[^0-9A-Z_a-z]*?l[^0-9A-Z_a-z]*?e|v[^0-9A-Z_a-z]*?g|e[^0-9A-Z_a-z]*?t[^0-9>A-Z_a-z])|f[^0-9A-Z_a-z]*?o[^0-9A-Z_a-z]*?r[^0-9A-Z_a-z]*?m|m[^0-9A-Z_a-z]*?(?:a[^0-9A-Z_a-z]*?r[^0-9A-Z_a-z]*?q[^0-9A-Z_a-z]*?u[^0-9A-Z_a-z]*?e[^0-9A-Z_a-z]*?e|e[^0-9A-Z_a-z]*?t[^0-9A-Z_a-z]*?a[^0-9>A-Z_a-z])|(?:l[^0-9A-Z_a-z]*?i[^0-9A-Z_a-z]*?n[^0-9A-Z_a-z]*?k|o[^0-9A-Z_a-z]*?b[^0-9A-Z_a-z]*?j[^0-9A-Z_a-z]*?e[^0-9A-Z_a-z]*?c[^0-9A-Z_a-z]*?t|e[^0-9A-Z_a-z]*?m[^0-9A-Z_a-z]*?b[^0-9A-Z_a-z]*?e[^0-9A-Z_a-z]*?d|a[^0-9A-Z_a-z]*?(?:p[^0-9A-Z_a-z]*?p[^0-9A-Z_a-z]*?l[^0-9A-Z_a-z]*?e[^0-9A-Z_a-z]*?t|u[^0-9A-Z_a-z]*?d[^0-9A-Z_a-z]*?i[^0-9A-Z_a-z]*?o|n[^0-9A-Z_a-z]*?i[^0-9A-Z_a-z]*?m[^0-9A-Z_a-z]*?a[^0-9A-Z_a-z]*?t[^0-9A-Z_a-z]*?e)|p[^0-9A-Z_a-z]*?a[^0-9A-Z_a-z]*?r[^0-9A-Z_a-z]*?a[^0-9A-Z_a-z]*?m|i?[^0-9A-Z_a-z]*?f[^0-9A-Z_a-z]*?r[^0-9A-Z_a-z]*?a[^0-9A-Z_a-z]*?m[^0-9A-Z_a-z]*?e|b[^0-9A-Z_a-z]*?(?:a[^0-9A-Z_a-z]*?s[^0-9A-Z_a-z]*?e|o[^0-9A-Z_a-z]*?d[^0-9A-Z_a-z]*?y|i[^0-9A-Z_a-z]*?n[^0-9A-Z_a-z]*?d[^0-9A-Z_a-z]*?i[^0-9A-Z_a-z]*?n[^0-9A-Z_a-z]*?g[^0-9A-Z_a-z]*?s)|i[^0-9A-Z_a-z]*?m[^0-9A-Z_a-z]*?a?[^0-9A-Z_a-z]*?g[^0-9A-Z_a-z]*?e?|v[^0-9A-Z_a-z]*?i[^0-9A-Z_a-z]*?d[^0-9A-Z_a-z]*?e[^0-9A-Z_a-z]*?o)[^0-9>A-Z_a-z])|(?:<[0-9A-Z_a-z].*[\s\v/]|[\"'](?:.*[\s\v/])?)(?:background|formaction|lowsrc|on(?:a(?:bort|ctivate|d(?:apteradded|dtrack)|fter(?:print|(?:scriptexecu|upda)te)|lerting|n(?:imation(?:end|iteration|start)|tennastatechange)|ppcommand|udio(?:end|process|start))|b(?:e(?:fore(?:(?:(?:de)?activa|scriptexecu)te|c(?:opy|ut)|editfocus|p(?:aste|rint)|u(?:nload|pdate))|gin(?:Event)?)|l(?:ocked|ur)|oun(?:ce|dary)|roadcast|usy)|c(?:a(?:(?:ch|llschang)ed|nplay(?:through)?|rdstatechange)|(?:ell|fstate)change|h(?:a(?:rging(?:time)?cha)?nge|ecking)|l(?:ick|ose)|o(?:m(?:mand(?:update)?|p(?:lete|osition(?:end|start|update)))|n(?:nect(?:ed|ing)|t(?:extmenu|rolselect))|py)|u(?:echange|t))|d(?:ata(?:(?:availabl|chang)e|error|setc(?:hanged|omplete))|blclick|e(?:activate|livery(?:error|success)|vice(?:found|light|(?:mo|orienta)tion|proximity))|i(?:aling|s(?:abled|c(?:hargingtimechange|onnect(?:ed|ing))))|o(?:m(?:a(?:ctivate|ttrmodified)|(?:characterdata|subtree)modified|focus(?:in|out)|mousescroll|node(?:inserted(?:intodocument)?|removed(?:fromdocument)?))|wnloading)|r(?:ag(?:drop|e(?:n(?:d|ter)|xit)|(?:gestur|leav)e|over|start)|op)|urationchange)|e(?:mptied|n(?:abled|d(?:ed|Event)?|ter)|rror(?:update)?|xit)|f(?:ailed|i(?:lterchange|nish)|o(?:cus(?:in|out)?|rm(?:change|input)))|g(?:amepad(?:axismove|button(?:down|up)|(?:dis)?connected)|et)|h(?:ashchange|e(?:adphoneschange|l[dp])|olding)|i(?:cc(?:cardlockerror|infochange)|n(?:coming|put|valid))|key(?:down|press|up)|l(?:evelchange|o(?:ad(?:e(?:d(?:meta)?data|nd)|start)?|secapture)|y)|m(?:ark|essage|o(?:use(?:down|enter|(?:lea|mo)ve|o(?:ut|ver)|up|wheel)|ve(?:end|start)?|z(?:a(?:fterpaint|udioavailable)|(?:beforeresiz|orientationchang|t(?:apgestur|imechang))e|(?:edgeui(?:c(?:ancel|omplet)|start)e|network(?:down|up)loa)d|fullscreen(?:change|error)|m(?:agnifygesture(?:start|update)?|ouse(?:hittest|pixelscroll))|p(?:ointerlock(?:change|error)|resstapgesture)|rotategesture(?:start|update)?|s(?:crolledareachanged|wipegesture(?:end|start|update)?))))|no(?:match|update)|o(?:(?:bsolet|(?:ff|n)lin)e|pen|verflow(?:changed)?)|p(?:a(?:ge(?:hide|show)|int|(?:st|us)e)|lay(?:ing)?|op(?:state|up(?:hid(?:den|ing)|show(?:ing|n)))|ro(?:gress|pertychange))|r(?:atechange|e(?:adystatechange|ceived|movetrack|peat(?:Event)?|quest|s(?:et|ize|u(?:lt|m(?:e|ing)))|trieving)|ow(?:e(?:nter|xit)|s(?:delete|inserted)))|s(?:croll|e(?:ek(?:complete|ed|ing)|lect(?:start)?|n(?:ding|t)|t)|how|(?:ound|peech)(?:end|start)|t(?:a(?:lled|rt|t(?:echange|uschanged))|k(?:comma|sessione)nd|op)|u(?:bmit|ccess|spend)|vg(?:abort|error|(?:un)?load|resize|scroll|zoom))|t(?:ext|ime(?:out|update)|ouch(?:cancel|en(?:d|ter)|(?:lea|mo)ve|start)|ransition(?:cancel|end|run))|u(?:n(?:derflow|load)|p(?:dateready|gradeneeded)|s(?:erproximity|sdreceived))|v(?:ersion|o(?:ic|lum)e)change|w(?:a(?:it|rn)ing|heel)|zoom)|ping|s(?:rc|tyle))[\x08-\n\f-\r ]*?=" \ "id:941160,\ phase:2,\ block,\ capture,\ t:none,t:utf8toUnicode,t:urlDecodeUni,t:htmlEntityDecode,t:jsDecode,t:cssDecode,t:removeNulls,\ msg:'NoScript XSS InjectionChecker: HTML Injection',\ logdata:'Matched Data: %{TX.0} found within %{MATCHED_VAR_NAME}: %{MATCHED_VAR}',\ tag:'application-multi',\ tag:'language-multi',\ tag:'platform-multi',\ tag:'attack-xss',\ tag:'paranoia-level/1',\ tag:'OWASP_CRS',\ tag:'capec/1000/152/242',\ ver:'OWASP_CRS/4.0.0-rc1',\ severity:'CRITICAL',\ setvar:'tx.xss_score=+%{tx.critical_anomaly_score}',\ setvar:'tx.inbound_anomaly_score_pl1=+%{tx.critical_anomaly_score}'" # # [NoScript InjectionChecker] Attributes injection # SecRule REQUEST_COOKIES|!REQUEST_COOKIES:/__utm/|REQUEST_COOKIES_NAMES|REQUEST_HEADERS:User-Agent|REQUEST_HEADERS:Referer|ARGS_NAMES|ARGS|REQUEST_FILENAME|XML:/* "@rx (?i)(?:\W|^)(?:javascript:(?:[\s\S]+[=\x5c\(\[\.<]|[\s\S]*?(?:\bname\b|\x5c[ux]\d))|data:(?:(?:[a-z]\w+/\w[\w+-]+\w)?[;,]|[\s\S]*?;[\s\S]*?\b(?:base64|charset=)|[\s\S]*?,[\s\S]*?<[\s\S]*?\w[\s\S]*?>))|@\W*?i\W*?m\W*?p\W*?o\W*?r\W*?t\W*?(?:/\*[\s\S]*?)?(?:[\"']|\W*?u\W*?r\W*?l[\s\S]*?\()|[^-]*?-\W*?m\W*?o\W*?z\W*?-\W*?b\W*?i\W*?n\W*?d\W*?i\W*?n\W*?g[^:]*?:\W*?u\W*?r\W*?l[\s\S]*?\(" \ "id:941170,\ phase:2,\ block,\ capture,\ t:none,t:utf8toUnicode,t:urlDecodeUni,t:htmlEntityDecode,t:jsDecode,t:cssDecode,t:removeNulls,\ msg:'NoScript XSS InjectionChecker: Attribute Injection',\ logdata:'Matched Data: %{TX.0} found within %{MATCHED_VAR_NAME}: %{MATCHED_VAR}',\ tag:'application-multi',\ tag:'language-multi',\ tag:'platform-multi',\ tag:'attack-xss',\ tag:'paranoia-level/1',\ tag:'OWASP_CRS',\ tag:'capec/1000/152/242',\ ver:'OWASP_CRS/4.0.0-rc1',\ severity:'CRITICAL',\ setvar:'tx.xss_score=+%{tx.critical_anomaly_score}',\ setvar:'tx.inbound_anomaly_score_pl1=+%{tx.critical_anomaly_score}'" # # [Deny List Keywords from Node-Validator] # https://raw.github.com/chriso/node-validator/master/validator.js # This rule has a stricter sibling 941181 (PL2) that covers the additional payload "-->" # SecRule REQUEST_COOKIES|!REQUEST_COOKIES:/__utm/|REQUEST_COOKIES_NAMES|ARGS_NAMES|ARGS|REQUEST_FILENAME|XML:/* "@pm document.cookie document.domain document.write .parentnode .innerhtml window.location -moz-binding " \ "id:941181,\ phase:2,\ block,\ capture,\ t:none,t:utf8toUnicode,t:urlDecodeUni,t:htmlEntityDecode,t:jsDecode,t:cssDecode,t:lowercase,t:removeNulls,\ msg:'Node-Validator Deny List Keywords',\ logdata:'Matched Data: %{TX.0} found within %{MATCHED_VAR_NAME}: %{MATCHED_VAR}',\ tag:'application-multi',\ tag:'language-multi',\ tag:'platform-multi',\ tag:'attack-xss',\ tag:'paranoia-level/2',\ tag:'OWASP_CRS',\ tag:'capec/1000/152/242',\ ver:'OWASP_CRS/4.0.0-rc1',\ severity:'CRITICAL',\ setvar:'tx.xss_score=+%{tx.critical_anomaly_score}',\ setvar:'tx.inbound_anomaly_score_pl2=+%{tx.critical_anomaly_score}'" # # -=[ XSS Filters from IE ]=- # Detect tags that are the most common direct HTML injection points. # # # # #