<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>Esperto on u-random</title><link>https://u-random.dev/tags/esperto/</link><description>Recent content in Esperto on u-random</description><generator>Hugo -- gohugo.io</generator><language>it-it</language><lastBuildDate>Mon, 08 Jun 2026 00:00:00 +0000</lastBuildDate><atom:link href="https://u-random.dev/tags/esperto/index.xml" rel="self" type="application/rss+xml"/><item><title>Cisco Packet Tracer: La Rete che Protegge Se Stessa</title><link>https://u-random.dev/blog/cisco-packet-tracer-la-rete-che-protegge-se-stessa/</link><pubDate>Mon, 08 Jun 2026 00:00:00 +0000</pubDate><guid>https://u-random.dev/blog/cisco-packet-tracer-la-rete-che-protegge-se-stessa/</guid><description>&lt;p&gt;


&lt;/p&gt;
&lt;div style="border-left:3px solid #6366f1;background:rgba(99,102,241,0.06);padding:12px 16px;border-radius:0 6px 6px 0;margin:1.5rem 0;"&gt;
 &lt;div style="font-size:0.7rem;font-weight:800;letter-spacing:0.1em;color:#6366f1;text-transform:uppercase;margin-bottom:6px;"&gt;TL;DR&lt;/div&gt;
 &lt;div style="font-size:0.95rem;line-height:1.6;"&gt;&lt;ul&gt;
&lt;li&gt;Una DMZ e' una zona di mezzo: esposta verso internet, isolata dalla LAN&lt;/li&gt;
&lt;li&gt;Due firewall significa che anche se Sofia/nginx viene compromessa, Giulia/MySQL e' ancora protetta da FW2&lt;/li&gt;
&lt;li&gt;Su ASA il traffico da security-level basso verso alto e' bloccato per default - non serve scrivere nessuna regola di blocco&lt;/li&gt;
&lt;/ul&gt;
&lt;/div&gt;
&lt;/div&gt;

&lt;details style="border-left:3px solid #10b981;background:rgba(16,185,129,0.06);border-radius:0 6px 6px 0;margin:1.5rem 0;"&gt;
 &lt;summary style="padding:10px 16px;font-size:0.7rem;font-weight:800;letter-spacing:0.1em;color:#10b981;text-transform:uppercase;cursor:pointer;list-style:none;display:flex;align-items:center;gap:8px;"&gt;
 &lt;span style="font-size:0.65rem;transition:transform 0.2s;"&gt;▶&lt;/span&gt; $ history
 &lt;/summary&gt;
 &lt;div style="padding:4px 16px 12px;font-size:0.92rem;line-height:1.7;font-family:'JetBrains Mono','Fira Code',monospace;"&gt;&lt;ul&gt;
&lt;li&gt;&lt;code&gt;nameif&lt;/code&gt; - assegna nome logico all'interfaccia ASA (outside, dmz, inside)&lt;/li&gt;
&lt;li&gt;&lt;code&gt;security-level&lt;/code&gt; - livello di fiducia: 0=esterno, 50=DMZ, 100=LAN&lt;/li&gt;
&lt;li&gt;&lt;code&gt;route outside 0.0.0.0 0.0.0.0 x.x.x.x&lt;/code&gt; - default route su ASA&lt;/li&gt;
&lt;li&gt;&lt;code&gt;show nameif&lt;/code&gt; - interfacce ASA con security level&lt;/li&gt;
&lt;/ul&gt;
&lt;/div&gt;
&lt;/details&gt;

&lt;hr&gt;

&lt;h2 class="relative group"&gt;Perche' questo lab
 &lt;div id="perche-questo-lab" class="anchor"&gt;&lt;/div&gt;
 
 &lt;span
 class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100 select-none"&gt;
 &lt;a class="text-primary-300 dark:text-neutral-700 !no-underline" href="#perche-questo-lab" aria-label="Anchor"&gt;#&lt;/a&gt;
 &lt;/span&gt;
 
&lt;/h2&gt;
&lt;p&gt;corsobitcoin.com e' una piattaforma di corsi online. Ha iscritti, sessioni, video, dati di pagamento.&lt;/p&gt;</description></item><item><title>chmod +s - il bit che dimentichi e l'attaccante trova</title><link>https://u-random.dev/blog/privilege-escalation-via-suid/</link><pubDate>Mon, 23 Mar 2026 00:00:00 +0000</pubDate><guid>https://u-random.dev/blog/privilege-escalation-via-suid/</guid><description>&lt;p&gt;


&lt;/p&gt;
&lt;div style="border-left:3px solid #6366f1;background:rgba(99,102,241,0.06);padding:12px 16px;border-radius:0 6px 6px 0;margin:1.5rem 0;"&gt;
 &lt;div style="font-size:0.7rem;font-weight:800;letter-spacing:0.1em;color:#6366f1;text-transform:uppercase;margin-bottom:6px;"&gt;TL;DR&lt;/div&gt;
 &lt;div style="font-size:0.95rem;line-height:1.6;"&gt;&lt;ul&gt;
&lt;li&gt;SUID forza l'EUID al proprietario del file al momento dell'esecuzione - se il proprietario è root, ogni utente che lo esegue ottiene EUID=0&lt;/li&gt;
&lt;li&gt;Un interprete con SUID root (python3, perl, bash) è escalation immediata: nessuna vulnerabilità da sfruttare, nessun exploit da compilare&lt;/li&gt;
&lt;li&gt;&lt;code&gt;find / -perm -4000 -type f 2&amp;gt;/dev/null&lt;/code&gt; in 30 secondi elenca tutto quello che conta&lt;/li&gt;
&lt;li&gt;Detection: baseline snapshot dei SUID in CI/CD + auditd rule su &lt;code&gt;execve&lt;/code&gt; con &lt;code&gt;euid=0&lt;/code&gt; e &lt;code&gt;auid!=unset&lt;/code&gt;&lt;/li&gt;
&lt;/ul&gt;
&lt;/div&gt;
&lt;/div&gt;

&lt;details style="border-left:3px solid #10b981;background:rgba(16,185,129,0.06);border-radius:0 6px 6px 0;margin:1.5rem 0;"&gt;
 &lt;summary style="padding:10px 16px;font-size:0.7rem;font-weight:800;letter-spacing:0.1em;color:#10b981;text-transform:uppercase;cursor:pointer;list-style:none;display:flex;align-items:center;gap:8px;"&gt;
 &lt;span style="font-size:0.65rem;transition:transform 0.2s;"&gt;▶&lt;/span&gt; $ history
 &lt;/summary&gt;
 &lt;div style="padding:4px 16px 12px;font-size:0.92rem;line-height:1.7;font-family:'JetBrains Mono','Fira Code',monospace;"&gt;&lt;ul&gt;
&lt;li&gt;&lt;a href="https://u-random.dev/comandi/find/" &gt;find&lt;/a&gt; -perm -4000 -type f 2&amp;gt;/dev/null&lt;/li&gt;
&lt;li&gt;stat /usr/bin/python3&lt;/li&gt;
&lt;li&gt;id&lt;/li&gt;
&lt;li&gt;cat /proc/self/status&lt;/li&gt;
&lt;li&gt;python3 -c &amp;quot;import os; os.execl('/bin/sh', 'sh', '-p')&amp;quot;&lt;/li&gt;
&lt;li&gt;auditctl -l&lt;/li&gt;
&lt;li&gt;ausearch -m execve -k suid_exec&lt;/li&gt;
&lt;li&gt;&lt;a href="https://u-random.dev/comandi/ls/" &gt;ls&lt;/a&gt; -la /usr/bin/python3&lt;/li&gt;
&lt;/ul&gt;
&lt;/div&gt;
&lt;/details&gt;

&lt;p&gt;Sono le 02:41. Il SIEM ha alzato un flag su &lt;code&gt;prod-api-03&lt;/code&gt;: processo root con parent &lt;code&gt;python3&lt;/code&gt;, nessun deploy in corso, nessuna maintenance window schedulata. Il processo è già terminato quando apro il ticket. Non c'è output, non c'è file scritto. Solo un'esecuzione anomala durata undici secondi.&lt;/p&gt;</description></item></channel></rss>