//This is a 1 line comment/* This is a multiline comment*/#!This is a 1 line comment, but "#!" must to be at the beggining of the line-->This is a 1 line comment, but "-->" must to be at the beggining of the linefor (let j =0; j <128; j++) {for (let k =0; k <128; k++) {for (let l =0; l <128; l++) {if (j ==34|| k ==34|| l ==34)continue;if (j ==0x0a|| k ==0x0a|| l ==0x0a)continue;if (j ==0x0d|| k ==0x0d|| l ==0x0d)continue;if (j ==0x3c|| k ==0x3c|| l ==0x3c)continue;if ((j ==47&& k ==47)||(k ==47&& l ==47))continue;try {var cmd =String.fromCharCode(j) +String.fromCharCode(k) +String.fromCharCode(l) +'a.orange.ctf"';eval(cmd);} catch(e) {var err =e.toString().split('\n')[0].split(':')[0];if (err ==='SyntaxError'|| err ==="ReferenceError")continueerr =e.toString().split('\n')[0]}console.log(err,cmd);}}}//From: https://balsn.tw/ctf_writeup/20191012-hitconctfquals/#bounty-pl33z// From: Heyes, Gareth. JavaScript for hackers: Learn to think like a hacker (p. 43). Kindle Edition.log=[];for(let i=0;i<=0xff;i++){for(let j=0;j<=0xfff;j++){try {eval(`${String.fromCodePoint(i,j)}%$£234$`)log.push([i,j])}catch(e){}}}console.log(log)//[35,33],[47,47]
Caratteri di Nuova Riga JS Validi
//Javascript interpret as new line these chars:String.fromCharCode(10) //0x0aString.fromCharCode(13) //0x0dString.fromCharCode(8232) //0xe2 0x80 0xa8String.fromCharCode(8233) //0xe2 0x80 0xa8for (let j =0; j <65536; j++) {try {var cmd ='"aaaaa";'+String.fromCharCode(j) +'-->a.orange.ctf"';eval(cmd);} catch(e) {var err =e.toString().split('\n')[0].split(':')[0];if (err ==='SyntaxError'|| err ==="ReferenceError")continue;err =e.toString().split('\n')[0]}console.log(`[${err}]`,j,cmd);}//From: https://balsn.tw/ctf_writeup/20191012-hitconctfquals/#bounty-pl33z
Spazi JS Validi nella chiamata di funzione
// Heyes, Gareth. JavaScript for hackers: Learn to think like a hacker (pp. 40-41). Kindle Edition.// Check chars that can be put in between in func name and the ()functionx(){}log=[];for(let i=0;i<=0x10ffff;i++){try {eval(`x${String.fromCodePoint(i)}()`)log.push(i)}catch(e){}}console.log(log)v//9,10,11,12,13,32,160,5760,8192,8193,8194,8195,8196,8197,8198,8199,8200,8201,8202,813 232,8233,8239,8287,12288,65279
Caratteri validi per generare stringhe
// Heyes, Gareth. JavaScript for hackers: Learn to think like a hacker (pp. 41-42). Kindle Edition.// Check which pairs of chars can make something be a valid stringlog=[];for(let i=0;i<=0x10ffff;i++){try {eval(`${String.fromCodePoint(i)}%$£234${String.fromCodePoint(i)}`)log.push(i)}catch(e){}}console.log(log) //34,39,47,96//single quote, quotes, backticks & // (regex)
Surrogate Pairs BF
Questa tecnica non sarà molto utile per XSS, ma potrebbe essere utile per bypassare le protezioni WAF. Questo codice Python riceve come input 2 byte e cerca una coppia surrogata che ha il primo byte come l'ultimo byte della coppia surrogata alta e l'ultimo byte come l'ultimo byte della coppia surrogata bassa.
def unicode(findHex):for i inrange(0,0xFFFFF):H =hex(int(((i -0x10000) /0x400) +0xD800))h =chr(int(H[-2:],16))L =hex(int(((i -0x10000) %0x400+0xDC00)))l =chr(int(L[-2:],16))if(h == findHex[0]) and (l == findHex[1]):print(H.replace("0x","\\u")+L.replace("0x","\\u"))
// Heyes, Gareth. JavaScript for hackers: Learn to think like a hacker (p. 34). Kindle Edition.log=[];let anchor =document.createElement('a');for(let i=0;i<=0x10ffff;i++){anchor.href =`javascript${String.fromCodePoint(i)}:`;if(anchor.protocol ==='javascript:') {log.push(i);}}console.log(log)//9,10,13,58// Note that you could BF also other possitions of the use of multiple chars// Test one optionlet anchor =document.createElement('a');anchor.href =`javascript${String.fromCodePoint(58)}:alert(1337)`;anchor.append('Click me')document.body.append(anchor)// Another way to test<ahref="javascript:alert(1337)">Test</a>
URL Fuzzing
// Heyes, Gareth. JavaScript for hackers: Learn to think like a hacker (pp. 36-37). Kindle Edition.// Before the protocola=document.createElement('a');log=[];for(let i=0;i<=0x10ffff;i++){a.href =`${String.fromCodePoint(i)}https://hacktricks.xyz`;if(a.hostname ==='hacktricks.xyz'){log.push(i);}}console.log(log) //0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32// Between the slashesa=document.createElement('a');log=[];for(let i=0;i<=0x10ffff;i++){a.href =`/${String.fromCodePoint(i)}/hacktricks.xyz`;if(a.hostname ==='hacktricks.xyz'){log.push(i);}}console.log(log) //9,10,13,47,92
HTML Fuzzing
// Heyes, Gareth. JavaScript for hackers: Learn to think like a hacker (p. 38). Kindle Edition.// Fuzzing chars that can close an HTML commentlet log=[];let div =document.createElement('div');for(let i=0;i<=0x10ffff;i++){div.innerHTML=`<!----${String.fromCodePoint(i)}><span></span>-->`;if(div.querySelector('span')){log.push(i);}}console.log(log)//33,45,62
L'operatore di decremento -- è anche un'assegnazione. Questo operatore prende un valore e poi lo decrementa di uno. Se quel valore non è un numero, verrà impostato su NaN. Questo può essere usato per rimuovere il contenuto delle variabili dall'ambiente.
Trucci delle Funzioni
.call e .apply
Il metodo .call di una funzione è usato per eseguire la funzione.
Il primo argomento che si aspetta per impostazione predefinita è il valore di this e se niente viene fornito, window sarà quel valore (a meno che non sia strict mode).
functiontest_call(){console.log(this.value); //baz}new_this={value:"hey!"}test_call.call(new_this);// To pass more arguments, just pass then inside .call()functiontest_call() {console.log(arguments[0]); //"arg1"console.log(arguments[1]); //"arg2"console.log(this); //[object Window]}test_call.call(null,"arg1","arg2")// If you use the "use strict" directive "this" will be null instead of window:functiontest_call() {"use strict";console.log(this); //null}test_call.call(null)//The apply function is pretty much exactly the same as the call function with one important difference, you can supply an array of arguments in the second argument:functiontest_apply() {console.log(arguments[0]); //"arg1"console.log(arguments[1]); //"arg2"console.log(this); //[object Window]}test_apply.apply(null, ["arg1","arg2"])
Funzioni freccia
Le funzioni freccia ti permettono di generare funzioni in una sola riga più facilmente (se le comprendi)
// Traditionalfunction (a){ return a +1; }// Arrow formsa => a +100;a => {a +100};// Traditionalfunction (a, b){ return a + b +1; }// Arrow(a, b) => a + b +100;// Tradictional no argslet a =4;let b =2;function (){ return a + b +1; }// Arrowlet a =4;let b =2;() => a + b +1;
Quindi, la maggior parte delle funzioni precedenti sono in realtà inutili perché non le stiamo salvando da nessuna parte per salvarle e chiamarle. Esempio di creazione della funzione plusone:
// Traductionalfunctionplusone (a){ return a +1; }//Arrowplusone= a => a +100;
Bind function
La funzione bind consente di creare una copia di una funzione modificando l'oggetto this e i parametri forniti.
//This will use the this object and print "Hello World"varfn=function ( param1, param2 ) {console.info( this, param1, param2 );}fn('Hello','World')//This will still use the this object and print "Hello World"var copyFn =fn.bind();copyFn('Hello','World')//This will use the "console" object as "this" object inside the function and print "fixingparam1 Hello"var bindFn_change =fn.bind(console,"fixingparam1");bindFn_change('Hello','World')//This will still use the this object and print "fixingparam1 Hello"var bindFn_thisnull =fn.bind(null,"fixingparam1");bindFn_change('Hello','World')//This will still use the this object and print "fixingparam1 Hello"var bindFn_this =fn.bind(this,"fixingparam1");bindFn_change('Hello','World')
Nota che usando bind puoi manipolare l'oggetto this che verrà utilizzato quando si chiama la funzione.
Rivelazione del codice della funzione
Se puoi accedere all'oggetto di una funzione puoi ottenere il codice di quella funzione.
functionafunc(){return1+1;}console.log(afunc.toString()); //This will print the code of the functionconsole.log(String(afunc)); //This will print the code of the functionconsole.log(this.afunc.toString()); //This will print the code of the functionconsole.log(global.afunc.toString()); //This will print the code of the function
In casi in cui la funzione non ha alcun nome, puoi comunque stampare il codice della funzione dall'interno:
L'oggetto Window consente di accedere a funzioni definite globalmente come alert o eval.
// Some ways to access windowwindow.eval("alert(1)")framesglobalThisparentselftop //If inside a frame, this is top most window// Access window from documentdocument.defaultView.alert(1)// Access document from a node objectnode =document.createElement('div')node.ownerDocument.defaultView.alert(1)// There is a path property on each error event whose last element is the window<imgsrconerror=event.path.pop().alert(1337)>// In other browsers the method is<img srconerror=event.composedPath().pop().alert(1337)>// In case of svg, the "event" object is called "evt"<svg><image href=1 onerror=evt.composedPath().pop().alert(1337)>// Abusing Error.prepareStackTrace to get Window backError.prepareStackTrace=function(error, callSites){2 callSites.shift().getThis().alert(1337);3 };4 new Error().stack// From an HTML event// Events from HTML are executed in this contextwith(document) {with(element) {//executed event}}// Because of that with(document) it's possible to access properties of document like:<img srconerror=defaultView.alert(1337)><img srconerror=s=createElement('script');s.append('alert(1337)');appendChild(s)>
Punto di interruzione sull'accesso al valore
// Stop when a property in sessionStorage or localStorage is set/get// via getItem or setItem functionssessionStorage.getItem =localStorage.getItem=function(prop) {debugger;return sessionStorage[prop];}localStorage.setItem=function(prop, val) {debugger;localStorage[prop] = val;}
// Stop when anyone sets or gets the property "ppmap" in any object// For example sessionStorage.ppmap// "123".ppmap// Useful to find where weird properties are being set or accessed// or to find where prototype pollutions are occurringfunctiondebugAccess(obj, prop, debugGet=true){var origValue = obj[prop];Object.defineProperty(obj, prop, {get:function () {if ( debugGet )debugger;return origValue;},set:function(val) {debugger;origValue = val;}});};debugAccess(Object.prototype,'ppmap')
Accesso automatico del browser per testare i payloads
//Taken from https://github.com/svennergr/writeups/blob/master/inti/0621/README.mdconstpuppeteer=require("puppeteer");constrealPasswordLength=3000;asyncfunctionsleep(ms) {returnnewPromise((resolve) =>setTimeout(resolve, ms));}(async () => {constbrowser=awaitpuppeteer.launch();constpage=awaitbrowser.newPage();//Loop to iterate through different valuesfor (let i =0; i <10000; i +=100) {console.log(`Run number ${i}`);constinput=`${"0".repeat(i)}${realPasswordLength}`;console.log(` https://challenge-0621.intigriti.io/passgen.php?passwordLength=${input}&allowNumbers=true&allowSymbols=true×tamp=1624556811000`);//Go to the pageawaitpage.goto(`https://challenge-0621.intigriti.io/passgen.php?passwordLength=${input}&allowNumbers=true&allowSymbols=true×tamp=1624556811000`);//Call function "generate()" inside the pageawaitpage.evaluate("generate()");//Get node inner text from an HTML elementconstpasswordContent=awaitpage.$$eval(".alert .page-content",(node) => node[0].innerText);//Transform the content and print it in consoleconstplainPassword=passwordContent.replace("Your password is: ","");if (plainPassword.length!= realPasswordLength) {console.log(i,plainPassword.length, plainPassword);}awaitsleep(1000);}awaitbrowser.close();})();
