Patrik Grobshäuser

On marketing claims nobody checks, the 1,000 projects Anthropic never listed, and why an industry full of experts followed along.

Credentials recoverable from a logistics platform's own tracking interface.

Unauthenticated SQL injection reachable in Drupal core.

Bug bounty platforms never humanized researchers or triage.

Reading arbitrary files pre-authentication, as root, on cPanel.

Tooling for reverse engineering without waiting on vendor firmware.

Every tool in h1-brain, explained.

h1-brain is an MCP server that gives Claude your HackerOne bounty history and a database of public disclosures.

A start-to-finish walkthrough of using h1-brain on an actual program.

Opus 4.6, the pentesting hype, and why most of the AI discourse around security is just noise.

Real usage patterns for an AI email agent — morning triage, thread summaries, draft replies, and where the human stays in the loop.

A four-layer defense model for AI email agents — because no single safety measure is enough when your inbox is on the line.

Defining hard rules, tone guidelines, and PII handling for an AI email agent — because ‘be helpful’ isn’t a security policy.

Installing the Gmail MCP server, configuring agent tools, and filtering down to only the operations you actually want.

Setting up Google Cloud OAuth credentials with minimal scopes for an AI email agent — because ‘full access’ is never the right default.

Running Obsidian in a headless Docker container with Obsidian Sync, giving AI agents direct access to your vault.

Using OAuth credentials from a Claude Max subscription to power OpenClaw agents, and wiring up a Telegram bot for mobile access.

Putting the OpenClaw Control UI behind HTTPS with basic auth, WebSocket passthrough, and a proper Content Security Policy — all through Nginx Proxy Manager.

Getting Node.js 22 and OpenClaw running on a fresh Hetzner CAX ARM64 Ubuntu Noble server — including the ARM64 gotchas nobody warns you about.

A full lab build and exploitation walkthrough for exposed Jolokia JMX endpoints: reflected XSS (CVE-2018-1000129), JNDI remote code execution via a rogue LDAP server (CVE-2018-1000130), and dumping the Java heap to recover credentials.

A VPS-based workflow chaining Aquatone subdomain discovery, WebScreenshot capture and express-photo-gallery into a browsable wall of screenshots for triaging a large attack surface.

A walkthrough of installing the Burp CA on an Android device, running frida-server and using an SSL re-pinning Frida script to intercept traffic from apps that pin certificates.

Directory brute-forcing a private bug bounty target turned up a world-readable .htpasswd whose descrypt hash, once cracked, opened four staging and development subdomains.

An XSS payload stored as a Google Cloud project name executed months later in the unfiltered project-deletion error message, earning a $5,000 VRP reward, plus the impact argument that got it past a self-XSS classification.

An in-scope Shopify POS endpoint exposed the card reader’s firmware bundles, which unpack via binwalk, a dd carve at 0x202024 and jffs2dump into a JFFS2 root filesystem containing a salted MD5 root hash.

Proxying OS X Spotlight through Burp showed it shipping the user’s latitude and longitude to api.smoot.apple.com on every search, with two ways to block the request.

PayPal’s invoicing feature accepted .xml attachments, and an XHTML-namespaced script element inside the XML executed when the file was served back.

A duplicated q parameter in PayPal’s merchant directory let an injected payload break out of script context, producing a reflected XSS that PayPal patched within days.

mailroom.prezi.com concatenated the request path onto its own hostname when redirecting, so a request to /.attacker-domain sent victims to a lookalike attacker-controlled host.

Results from two weeks of a Kippo SSH honeypot in November 2014: roughly 4,000 brute-force attempts, 2,500 distinct credential pairs, and a source distribution dominated by hosts in China.

A Firefox-only reflected XSS on wwwb.search.billmelater.com, achieved by closing out of a style attribute and injecting a fresh script element, which the vendor classified as out of scope.

A stored XSS in PayPal’s account name field, delivered to arbitrary users through invoices after bypassing the signup flow’s security check by truncating the workflow URL to /webapps/.

A payload placed in the URL fragment reached a DOM sink on PayPal’s main domain and executed; PayPal closed the report as a duplicate.

Google Tag Manager validated macro names in the web UI but not in the JSON container import path, so a payload smuggled through a file upload executed and earned a $5,000 bounty.

WP Live Chat Support, MyLiveChat and Provide Support all accepted stored cross-site scripting during a 2014 customer install.

Chrome resolves and executes a script URL written as http: followed by any number of backslashes.

A path traversal issue on Prezi’s map.prezi.com subdomain, fixed within two days of reporting and rewarded with a $1,000 bounty.

A 2014 run through PayPal’s bug bounty scope: seven confirmed issues across paypal.com, financing.paypal.com, apps.paypal.com and the paypal-*.com family, all closed as duplicate or invalid.

Reflected cross-site scripting across 160 German tax office websites, disclosed via heise.de and forwarded to CERT-Bund for coordinated remediation.

A public PHP 5.3.3-5.3.6 socket_connect exploit carrying a bind-TCP shell payload, dropped as an uploaded PHP file and located with an nmap sweep of ports 4000-4500.

Chaining a login-form SQL injection through sqlmap’s –os-shell into a Linux 2.6.32 local root exploit to go from the ’nobody’ user to full control of the server.

Defeating iTunes’ ptrace-based anti-debugging on OS X by breaking on ptrace and rewriting the rdi register, and porting the bypass from Apple’s GDB to LLDB to get a Python-capable debugger.

What I do, and where I have done it.

Pivoting from Yahoo’s main A record to its ARIN netblock and sweeping all 260,000 addresses in the /14 for an exposed phpinfo.php.