Security ❀ JavaScript Attacks 前端攻击

原创

无糖可乐没有灵魂 2022-12-16 22:39:44 博主文章分类：Web Security ©著作权

文章标签 javascript 前端开发语言 i++ bc 文章分类 运维

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文章目录

JavaScript Attacks 前端攻击

1 Low Level
2 Medium Level
3 High Level
4 Impossible Level

JavaScript Attacks 前端攻击

JavaScript是一种基于对象和事件驱动的、并具有安全性能的脚本语言。是一种解释型语言（代码不需要进行预编译）。通常JavaScript脚本是通过嵌入在HTML中来实现自身的功能的；若是涉及到Cookie、Session等记录用户信息的脚本，应该通过外部引入方式，并且不能暴露文件路径，控制好文件访问权限，若被攻击者获取到重要脚本代码，则能伪造其他合法用户进行伪造。

1 Low Level

源码：

<?php
$page[ 'body' ] .= <<<EOF
<script>

/*
MD5 code from here
https://github.com/blueimp/JavaScript-MD5
*/

!function(n){"use strict";function t(n,t){var r=(65535&n)+(65535&t);return(n>>16)+(t>>16)+(r>>16)<<16|65535&r}function r(n,t){return n<<t|n>>>32-t}function e(n,e,o,u,c,f){return t(r(t(t(e,n),t(u,f)),c),o)}function o(n,t,r,o,u,c,f){return e(t&r|~t&o,n,t,u,c,f)}function u(n,t,r,o,u,c,f){return e(t&o|r&~o,n,t,u,c,f)}function c(n,t,r,o,u,c,f){return e(t^r^o,n,t,u,c,f)}function f(n,t,r,o,u,c,f){return e(r^(t|~o),n,t,u,c,f)}function i(n,r){n[r>>5]|=128<<r%32,n[14+(r+64>>>9<<4)]=r;var e,i,a,d,h,l=1732584193,g=-271733879,v=-1732584194,m=271733878;for(e=0;e<n.length;e+=16)i=l,a=g,d=v,h=m,g=f(g=f(g=f(g=f(g=c(g=c(g=c(g=c(g=u(g=u(g=u(g=u(g=o(g=o(g=o(g=o(g,v=o(v,m=o(m,l=o(l,g,v,m,n[e],7,-680876936),g,v,n[e+1],12,-389564586),l,g,n[e+2],17,606105819),m,l,n[e+3],22,-1044525330),v=o(v,m=o(m,l=o(l,g,v,m,n[e+4],7,-176418897),g,v,n[e+5],12,1200080426),l,g,n[e+6],17,-1473231341),m,l,n[e+7],22,-45705983),v=o(v,m=o(m,l=o(l,g,v,m,n[e+8],7,1770035416),g,v,n[e+9],12,-1958414417),l,g,n[e+10],17,-42063),m,l,n[e+11],22,-1990404162),v=o(v,m=o(m,l=o(l,g,v,m,n[e+12],7,1804603682),g,v,n[e+13],12,-40341101),l,g,n[e+14],17,-1502002290),m,l,n[e+15],22,1236535329),v=u(v,m=u(m,l=u(l,g,v,m,n[e+1],5,-165796510),g,v,n[e+6],9,-1069501632),l,g,n[e+11],14,643717713),m,l,n[e],20,-373897302),v=u(v,m=u(m,l=u(l,g,v,m,n[e+5],5,-701558691),g,v,n[e+10],9,38016083),l,g,n[e+15],14,-660478335),m,l,n[e+4],20,-405537848),v=u(v,m=u(m,l=u(l,g,v,m,n[e+9],5,568446438),g,v,n[e+14],9,-1019803690),l,g,n[e+3],14,-187363961),m,l,n[e+8],20,1163531501),v=u(v,m=u(m,l=u(l,g,v,m,n[e+13],5,-1444681467),g,v,n[e+2],9,-51403784),l,g,n[e+7],14,1735328473),m,l,n[e+12],20,-1926607734),v=c(v,m=c(m,l=c(l,g,v,m,n[e+5],4,-378558),g,v,n[e+8],11,-2022574463),l,g,n[e+11],16,1839030562),m,l,n[e+14],23,-35309556),v=c(v,m=c(m,l=c(l,g,v,m,n[e+1],4,-1530992060),g,v,n[e+4],11,1272893353),l,g,n[e+7],16,-155497632),m,l,n[e+10],23,-1094730640),v=c(v,m=c(m,l=c(l,g,v,m,n[e+13],4,681279174),g,v,n[e],11,-358537222),l,g,n[e+3],16,-722521979),m,l,n[e+6],23,76029189),v=c(v,m=c(m,l=c(l,g,v,m,n[e+9],4,-640364487),g,v,n[e+12],11,-421815835),l,g,n[e+15],16,530742520),m,l,n[e+2],23,-995338651),v=f(v,m=f(m,l=f(l,g,v,m,n[e],6,-198630844),g,v,n[e+7],10,1126891415),l,g,n[e+14],15,-1416354905),m,l,n[e+5],21,-57434055),v=f(v,m=f(m,l=f(l,g,v,m,n[e+12],6,1700485571),g,v,n[e+3],10,-1894986606),l,g,n[e+10],15,-1051523),m,l,n[e+1],21,-2054922799),v=f(v,m=f(m,l=f(l,g,v,m,n[e+8],6,1873313359),g,v,n[e+15],10,-30611744),l,g,n[e+6],15,-1560198380),m,l,n[e+13],21,1309151649),v=f(v,m=f(m,l=f(l,g,v,m,n[e+4],6,-145523070),g,v,n[e+11],10,-1120210379),l,g,n[e+2],15,718787259),m,l,n[e+9],21,-343485551),l=t(l,i),g=t(g,a),v=t(v,d),m=t(m,h);return[l,g,v,m]}function a(n){var t,r="",e=32*n.length;for(t=0;t<e;t+=8)r+=String.fromCharCode(n[t>>5]>>>t%32&255);return r}function d(n){var t,r=[];for(r[(n.length>>2)-1]=void 0,t=0;t<r.length;t+=1)r[t]=0;var e=8*n.length;for(t=0;t<e;t+=8)r[t>>5]|=(255&n.charCodeAt(t/8))<<t%32;return r}function h(n){return a(i(d(n),8*n.length))}function l(n,t){var r,e,o=d(n),u=[],c=[];for(u[15]=c[15]=void 0,o.length>16&&(o=i(o,8*n.length)),r=0;r<16;r+=1)u[r]=909522486^o[r],c[r]=1549556828^o[r];return e=i(u.concat(d(t)),512+8*t.length),a(i(c.concat(e),640))}function g(n){var t,r,e="";for(r=0;r<n.length;r+=1)t=n.charCodeAt(r),e+="0123456789abcdef".charAt(t>>>4&15)+"0123456789abcdef".charAt(15&t);return e}function v(n){return unescape(encodeURIComponent(n))}function m(n){return h(v(n))}function p(n){return g(m(n))}function s(n,t){return l(v(n),v(t))}function C(n,t){return g(s(n,t))}function A(n,t,r){return t?r?s(t,n):C(t,n):r?m(n):p(n)}"function"==typeof define&&define.amd?define(function(){return A}):"object"==typeof module&&module.exports?module.exports=A:n.md5=A}(this);

    function rot13(inp) {
        return inp.replace(/[a-zA-Z]/g,function(c){return String.fromCharCode((c<="Z"?90:122)>=(c=c.charCodeAt(0)+13)?c:c-26);});
    }
    
    # 生成一个token与phrase值互相匹配即可，且token为phrase值经md5(rot13(phrase))获得
    function generate_token() {
        var phrase = document.getElementById("phrase").value;
        document.getElementById("token").value = md5(rot13(phrase));
    }

    generate_token();
</script>
EOF;
?>

因此只要将phrase值经md5(rot13(phrase))获得token即可，攻击案例success：38581812b435834ebf84ebcc2c6424d6。

Security ❀ JavaScript Attacks 前端攻击_i++

获取到token后，使用burp进行抓包重组参数后发送即可完成攻击。

Security ❀ JavaScript Attacks 前端攻击_前端_02

web页面效果如下：

Security ❀ JavaScript Attacks 前端攻击_bc_03

2 Medium Level

源码：

<?php
$page[ 'body' ] .= '<script src="' . DVWA_WEB_PAGE_TO_ROOT . 'vulnerabilities/javascript/source/medium.js"></script>';
?>

medium.js代码：

function do_something(e){for(var t="",n=e.length-1;n>=0;n--)t+=e[n];return t}setTimeout(function()
{do_elsesomething("XX")},300);function do_elsesomething(e){document.getElementById("token").value=do_something(e+document.getElementById("phrase").value+"XX")}
// 将phrase进行反转，并前后添加XX构成token

burp抓包如下：

Security ❀ JavaScript Attacks 前端攻击_前端_04

修改token与phrase的值后进行转发，触发攻击。

Security ❀ JavaScript Attacks 前端攻击_javascript_05

web页面效果如下：

Security ❀ JavaScript Attacks 前端攻击_i++_06

3 High Level

源码：

<?php
$page[ 'body' ] .= '<script src="' . DVWA_WEB_PAGE_TO_ROOT . 'vulnerabilities/javascript/source/high.js"></script>';
?>

high.js代码：

var a=['fromCharCode','toString','replace','BeJ','\x5cw+','Lyg','SuR','(w(){\x273M\x203L\x27;q\x201l=\x273K\x203I\x203J\x20T\x27;q\x201R=1c\x202I===\x271n\x27;q\x20Y=1R?2I:{};p(Y.3N){1R=1O}q\x202L=!1R&&1c\x202M===\x271n\x27;q\x202o=!Y.2S&&1c\x202d===\x271n\x27&&2d.2Q&&2d.2Q.3S;p(2o){Y=3R}z\x20p(2L){Y=2M}q\x202G=!Y.3Q&&1c\x202g===\x271n\x27&&2g.X;q\x202s=1c\x202l===\x27w\x27&&2l.3P;q\x201y=!Y.3H&&1c\x20Z!==\x272T\x27;q\x20m=\x273G\x27.3z(\x27\x27);q\x202w=[-3y,3x,3v,3w];q\x20U=[24,16,8,0];q\x20K=[3A,3B,3F,3E,3D,3C,3T,3U,4d,4c,4b,49,4a,4e,4f,4j,4i,4h,3u,48,47,3Z,3Y,3X,3V,3W,40,41,46,45,43,42,4k,3f,38,36,39,37,34,33,2Y,31,2Z,35,3t,3n,3m,3l,3o,3p,3s,3r,3q,3k,3j,3d,3a,3c,3b,3e,3h,3g,3i,4g];q\x201E=[\x271e\x27,\x2727\x27,\x271G\x27,\x272R\x27];q\x20l=[];p(Y.2S||!1z.1K){1z.1K=w(1x){A\x204C.Q.2U.1I(1x)===\x27[1n\x201z]\x27}}p(1y&&(Y.50||!Z.1N)){Z.1N=w(1x){A\x201c\x201x===\x271n\x27&&1x.1w&&1x.1w.1J===Z}}q\x202m=w(1X,x){A\x20w(s){A\x20O\x20N(x,1d).S(s)[1X]()}};q\x202a=w(x){q\x20P=2m(\x271e\x27,x);p(2o){P=2P(P,x)}P.1T=w(){A\x20O\x20N(x)};P.S=w(s){A\x20P.1T().S(s)};1g(q\x20i=0;i<1E.W;++i){q\x20T=1E[i];P[T]=2m(T,x)}A\x20P};q\x202P=w(P,x){q\x201S=2O(\x222N(\x271S\x27)\x22);q\x201Y=2O(\x222N(\x271w\x27).1Y\x22);q\x202n=x?\x271H\x27:\x271q\x27;q\x202z=w(s){p(1c\x20s===\x272p\x27){A\x201S.2x(2n).S(s,\x274S\x27).1G(\x271e\x27)}z{p(s===2q||s===2T){1u\x20O\x201t(1l)}z\x20p(s.1J===Z){s=O\x202r(s)}}p(1z.1K(s)||Z.1N(s)||s.1J===1Y){A\x201S.2x(2n).S(O\x201Y(s)).1G(\x271e\x27)}z{A\x20P(s)}};A\x202z};q\x202k=w(1X,x){A\x20w(G,s){A\x20O\x201P(G,x,1d).S(s)[1X]()}};q\x202f=w(x){q\x20P=2k(\x271e\x27,x);P.1T=w(G){A\x20O\x201P(G,x)};P.S=w(G,s){A\x20P.1T(G).S(s)};1g(q\x20i=0;i<1E.W;++i){q\x20T=1E[i];P[T]=2k(T,x)}A\x20P};w\x20N(x,1v){p(1v){l[0]=l[16]=l[1]=l[2]=l[3]=l[4]=l[5]=l[6]=l[7]=l[8]=l[9]=l[10]=l[11]=l[12]=l[13]=l[14]=l[15]=0;k.l=l}z{k.l=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]}p(x){k.C=4I;k.B=4H;k.E=4l;k.F=4U;k.J=4J;k.I=4K;k.H=4L;k.D=4T}z{k.C=4X;k.B=4W;k.E=4Y;k.F=4Z;k.J=4V;k.I=4O;k.H=4F;k.D=4s}k.1C=k.1A=k.L=k.2i=0;k.1U=k.1L=1O;k.2j=1d;k.x=x}N.Q.S=w(s){p(k.1U){A}q\x202h,T=1c\x20s;p(T!==\x272p\x27){p(T===\x271n\x27){p(s===2q){1u\x20O\x201t(1l)}z\x20p(1y&&s.1J===Z){s=O\x202r(s)}z\x20p(!1z.1K(s)){p(!1y||!Z.1N(s)){1u\x20O\x201t(1l)}}}z{1u\x20O\x201t(1l)}2h=1d}q\x20r,M=0,i,W=s.W,l=k.l;4t(M<W){p(k.1L){k.1L=1O;l[0]=k.1C;l[16]=l[1]=l[2]=l[3]=l[4]=l[5]=l[6]=l[7]=l[8]=l[9]=l[10]=l[11]=l[12]=l[13]=l[14]=l[15]=0}p(2h){1g(i=k.1A;M<W&&i<1k;++M){l[i>>2]|=s[M]<<U[i++&3]}}z{1g(i=k.1A;M<W&&i<1k;++M){r=s.1Q(M);p(r<R){l[i>>2]|=r<<U[i++&3]}z\x20p(r<2v){l[i>>2]|=(2t|(r>>6))<<U[i++&3];l[i>>2]|=(R|(r&V))<<U[i++&3]}z\x20p(r<2A||r>=2E){l[i>>2]|=(2D|(r>>12))<<U[i++&3];l[i>>2]|=(R|((r>>6)&V))<<U[i++&3];l[i>>2]|=(R|(r&V))<<U[i++&3]}z{r=2C+(((r&23)<<10)|(s.1Q(++M)&23));l[i>>2]|=(2X|(r>>18))<<U[i++&3];l[i>>2]|=(R|((r>>12)&V))<<U[i++&3];l[i>>2]|=(R|((r>>6)&V))<<U[i++&3];l[i>>2]|=(R|(r&V))<<U[i++&3]}}}k.2u=i;k.L+=i-k.1A;p(i>=1k){k.1C=l[16];k.1A=i-1k;k.1W();k.1L=1d}z{k.1A=i}}p(k.L>4r){k.2i+=k.L/2H<<0;k.L=k.L%2H}A\x20k};N.Q.1s=w(){p(k.1U){A}k.1U=1d;q\x20l=k.l,i=k.2u;l[16]=k.1C;l[i>>2]|=2w[i&3];k.1C=l[16];p(i>=4q){p(!k.1L){k.1W()}l[0]=k.1C;l[16]=l[1]=l[2]=l[3]=l[4]=l[5]=l[6]=l[7]=l[8]=l[9]=l[10]=l[11]=l[12]=l[13]=l[14]=l[15]=0}l[14]=k.2i<<3|k.L>>>29;l[15]=k.L<<3;k.1W()};N.Q.1W=w(){q\x20a=k.C,b=k.B,c=k.E,d=k.F,e=k.J,f=k.I,g=k.H,h=k.D,l=k.l,j,1a,1b,1j,v,1f,1h,1B,1Z,1V,1D;1g(j=16;j<1k;++j){v=l[j-15];1a=((v>>>7)|(v<<25))^((v>>>18)|(v<<14))^(v>>>3);v=l[j-2];1b=((v>>>17)|(v<<15))^((v>>>19)|(v<<13))^(v>>>10);l[j]=l[j-16]+1a+l[j-7]+1b<<0}1D=b&c;1g(j=0;j<1k;j+=4){p(k.2j){p(k.x){1B=4m;v=l[0]-4n;h=v-4o<<0;d=v+4p<<0}z{1B=4v;v=l[0]-4w;h=v-4G<<0;d=v+4D<<0}k.2j=1O}z{1a=((a>>>2)|(a<<30))^((a>>>13)|(a<<19))^((a>>>22)|(a<<10));1b=((e>>>6)|(e<<26))^((e>>>11)|(e<<21))^((e>>>25)|(e<<7));1B=a&b;1j=1B^(a&c)^1D;1h=(e&f)^(~e&g);v=h+1b+1h+K[j]+l[j];1f=1a+1j;h=d+v<<0;d=v+1f<<0}1a=((d>>>2)|(d<<30))^((d>>>13)|(d<<19))^((d>>>22)|(d<<10));1b=((h>>>6)|(h<<26))^((h>>>11)|(h<<21))^((h>>>25)|(h<<7));1Z=d&a;1j=1Z^(d&b)^1B;1h=(h&e)^(~h&f);v=g+1b+1h+K[j+1]+l[j+1];1f=1a+1j;g=c+v<<0;c=v+1f<<0;1a=((c>>>2)|(c<<30))^((c>>>13)|(c<<19))^((c>>>22)|(c<<10));1b=((g>>>6)|(g<<26))^((g>>>11)|(g<<21))^((g>>>25)|(g<<7));1V=c&d;1j=1V^(c&a)^1Z;1h=(g&h)^(~g&e);v=f+1b+1h+K[j+2]+l[j+2];1f=1a+1j;f=b+v<<0;b=v+1f<<0;1a=((b>>>2)|(b<<30))^((b>>>13)|(b<<19))^((b>>>22)|(b<<10));1b=((f>>>6)|(f<<26))^((f>>>11)|(f<<21))^((f>>>25)|(f<<7));1D=b&c;1j=1D^(b&d)^1V;1h=(f&g)^(~f&h);v=e+1b+1h+K[j+3]+l[j+3];1f=1a+1j;e=a+v<<0;a=v+1f<<0}k.C=k.C+a<<0;k.B=k.B+b<<0;k.E=k.E+c<<0;k.F=k.F+d<<0;k.J=k.J+e<<0;k.I=k.I+f<<0;k.H=k.H+g<<0;k.D=k.D+h<<0};N.Q.1e=w(){k.1s();q\x20C=k.C,B=k.B,E=k.E,F=k.F,J=k.J,I=k.I,H=k.H,D=k.D;q\x201e=m[(C>>28)&o]+m[(C>>24)&o]+m[(C>>20)&o]+m[(C>>16)&o]+m[(C>>12)&o]+m[(C>>8)&o]+m[(C>>4)&o]+m[C&o]+m[(B>>28)&o]+m[(B>>24)&o]+m[(B>>20)&o]+m[(B>>16)&o]+m[(B>>12)&o]+m[(B>>8)&o]+m[(B>>4)&o]+m[B&o]+m[(E>>28)&o]+m[(E>>24)&o]+m[(E>>20)&o]+m[(E>>16)&o]+m[(E>>12)&o]+m[(E>>8)&o]+m[(E>>4)&o]+m[E&o]+m[(F>>28)&o]+m[(F>>24)&o]+m[(F>>20)&o]+m[(F>>16)&o]+m[(F>>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上述js代码使用了典型的代码混淆手段，使得代码阅读难度提升，可以使用JavaScript代码在线恢复工具进行代码缩进恢复http://deobfuscatejavascript.com/，提升阅读效果，查找关键代码。

Security ❀ JavaScript Attacks 前端攻击_bc_07

关键代码如下：

function do_something(e) {
    for (var t = "", n = e.length - 1; n >= 0; n--) t += e[n];
    return t
}
function token_part_3(t, y = "ZZ") {
    document.getElementById("token").value = sha256(document.getElementById("token").value + y)
}
function token_part_2(e = "YY") {
    document.getElementById("token").value = sha256(e + document.getElementById("token").value)
}
function token_part_1(a, b) {
    document.getElementById("token").value = do_something(document.getElementById("phrase").value)
}
document.getElementById("phrase").value = "";
setTimeout(function() {
    token_part_2("XX")
}, 300);
// 执行token_part_2延时300ms
document.getElementById("send").addEventListener("click", token_part_3);
token_part_1("ABCD", 44);
// 执行token_part_1延时44ms