If you've disabled the specific rule that was matching, and you're still receiving a 403 error what is output in the Apache error logs?
So apache error logs weren't being helpful, they weren't showing anything wrong.
I checked the modsecurity logs and this log WAS showing why it was being blocked... yet the "ModSecurity Tools" in WHM wasn't showing it...
The rule 941160 was the cause (along with 941110) which is in /etc/apache2/conf.d/modsec_vendor_configs/OWASP3/rules/REQUST-941-APPLICATION-ATTACK-XSS.conf
For reference, the "logged data" is a copy of the page content using WordPress' "WPBakery Page Builder" shortcodes.. that seems to be a bit of a false positive.
Code:
Message: Access denied with code 403 (phase 2). Test 'REQUEST_COOKIES|!REQUEST_COOKIES:/__utm/|REQUEST_COOKIES_NAMES|REQUEST_HEADERS:User-Agent|REQUEST_HEADERS:Referer|ARGS_NAMES|ARGS|XML:/*' against '(?i)<[^\w<>]*(?:[^<>\"'\s]*:)?[^\w<>]*(?:\W*?s\W*?c\W*?r\W*?i\W*?p\W*?t|\W*?f\W*?o\W*?r\W*?m|\W*?s\W*?t\W*?y\W*?l\W*?e|\W*?s\W*?v\W*?g|\W*?m\W*?a\W*?r\W*?q\W*?u\W*?e\W*?e|(?:\W*?l\W*?i\W*?n\W*?k|\W*?o\W*?b\W*?j\W*?e\W*?c\W*?t|\W*?e\W*?m\W*?b\W*?e\W*?d|\W*?a\W*?p\W*?p\W*?l\W*?e\W*?t|\W*?p\W*?a\W*?r\W*?a\W*?m|\W*?i?\W*?f\W*?r\W*?a\W*?m\W*?e|\W*?b\W*?a\W*?s\W*?e|\W*?b\W*?o\W*?d\W*?y|\W*?m\W*?e\W*?t\W*?a|\W*?i\W*?m\W*?a?\W*?g\W*?e?|\W*?v\W*?i\W*?d\W*?e\W*?o|\W*?a\W*?u\W*?d\W*?i\W*?o|\W*?b\W*?i\W*?n\W*?d\W*?i\W*?n\W*?g\W*?s|\W*?s\W*?e\W*?t|\W*?a\W*?n\W*?i\W*?m\W*?a\W*?t\W*?e)[^>\w])|(?:<\w[\s\S]*[\s\/]|['\"](?:[\s\S]*[\s\/])?)(?:formaction|style|background|src|lowsrc|ping|on(?:d(?:e(?:vice(?:(?:orienta|mo)tion|proximity|found|light)|livery(?:success|error)|activate)|r(?:ag(?:e(?:n(?:ter|d)|xit)|(?:gestur|leav)e|start|drop|over)?|op)|i(?:s(?:c(?:hargingtimechange|onnect(?:ing|ed))|abled)|aling)|ata(?:setc(?:omplete|hanged)|(?:availabl|chang)e|error)|urationchange|ownloading|blclick)|Moz(?:M(?:agnifyGesture(?:Update|Start)?|ouse(?:PixelScroll|Hittest))|S(?:wipeGesture(?:Update|Start|End)?|crolledAreaChanged)|(?:(?:Press)?TapGestur|BeforeResiz)e|EdgeUI(?:C(?:omplet|ancel)|Start)ed|RotateGesture(?:Update|Start)?|A(?:udioAvailable|fterPaint))|c(?:o(?:m(?:p(?:osition(?:update|start|end)|lete)|mand(?:update)?)|n(?:t(?:rolselect|extmenu)|nect(?:ing|ed))|py)|a(?:(?:llschang|ch)ed|nplay(?:through)?|rdstatechange)|h(?:(?:arging(?:time)?ch)?ange|ecking)|(?:fstate|ell)change|u(?:echange|t)|l(?:ick|ose))|m(?:o(?:z(?:pointerlock(?:change|error)|(?:orientation|time)change|fullscreen(?:change|error)|network(?:down|up)load)|use(?:(?:lea|mo)ve|o(?:ver|ut)|enter|wheel|down|up)|ve(?:start|end)?)|essage|ark)|s(?:t(?:a(?:t(?:uschanged|echange)|lled|rt)|k(?:sessione|comma)nd|op)|e(?:ek(?:complete|ing|ed)|(?:lec(?:tstar)?)?t|n(?:ding|t))|u(?:ccess|spend|bmit)|peech(?:start|end)|ound(?:start|end)|croll|how)|b(?:e(?:for(?:e(?:(?:scriptexecu|activa)te|u(?:nload|pdate)|p(?:aste|rint)|c(?:opy|ut)|editfocus)|deactivate)|gin(?:Event)?)|oun(?:dary|ce)|l(?:ocked|ur)|roadcast|usy)|a(?:n(?:imation(?:iteration|start|end)|tennastatechange)|fter(?:(?:scriptexecu|upda)te|print)|udio(?:process|start|end)|d(?:apteradded|dtrack)|ctivate|lerting|bort)|DOM(?:Node(?:Inserted(?:IntoDocument)?|Removed(?:FromDocument)?)|(?:CharacterData|Subtree)Modified|A(?:ttrModified|ctivate)|Focus(?:Out|In)|MouseScroll)|r(?:e(?:s(?:u(?:m(?:ing|e)|lt)|ize|et)|adystatechange|pea(?:tEven)?t|movetrack|trieving|ceived)|ow(?:s(?:inserted|delete)|e(?:nter|xit))|atechange)|p(?:op(?:up(?:hid(?:den|ing)|show(?:ing|n))|state)|a(?:ge(?:hide|show)|(?:st|us)e|int)|ro(?:pertychange|gress)|lay(?:ing)?)|t(?:ouch(?:(?:lea|mo)ve|en(?:ter|d)|cancel|start)|ime(?:update|out)|ransitionend|ext)|u(?:s(?:erproximity|sdreceived)|p(?:gradeneeded|dateready)|n(?:derflow|load))|f(?:o(?:rm(?:change|input)|cus(?:out|in)?)|i(?:lterchange|nish)|ailed)|l(?:o(?:ad(?:e(?:d(?:meta)?data|nd)|start)?|secapture)|evelchange|y)|g(?:amepad(?:(?:dis)?connected|button(?:down|up)|axismove)|et)|e(?:n(?:d(?:Event|ed)?|abled|ter)|rror(?:update)?|mptied|xit)|i(?:cc(?:cardlockerror|infochange)|n(?:coming|valid|put))|o(?:(?:(?:ff|n)lin|bsolet)e|verflow(?:changed)?|pen)|SVG(?:(?:Unl|L)oad|Resize|Scroll|Abort|Error|Zoom)|h(?:e(?:adphoneschange|l[dp])|ashchange|olding)|v(?:o(?:lum|ic)e|ersion)change|w(?:a(?:it|rn)ing|heel)|key(?:press|down|up)|(?:AppComman|Loa)d|no(?:update|match)|Request|zoom))[\s\x08]*?=' is true. [file "/etc/apache2/conf.d/modsec_vendor_configs/OWASP3/rules/REQUEST-941-APPLICATION-ATTACK-XSS.conf"] [line "74"] [id "941160"] [rev "2"] [msg "NoScript XSS InjectionChecker: HTML Injection"]