Charalambos Emmanouilidis · OSCP Focus: Linux infrastructure Germany · remote

I attack your systems before someone else does.

Penetration testing with a focus on Linux infrastructure: servers, containers and Kubernetes – and the web applications running on them. AI-assisted reconnaissance, manual depth and a report your team can act on right away.

certifications
OSCP · SCP Web Application Security
methodology
BSI pentest guideline · OWASP WSTG
offensive_since
2019 · bug bounty, disclosure, pentests
reports
German · English
01 / services

What I test

linux · focus

Linux servers & infrastructure

Exposed services, SSH, sudo and file permissions, systemd units, firewall rules and privilege escalation – from attacker shell to root.

linux · container

Containers & Kubernetes

Container escapes, RBAC, network policies, secrets and images: how far does an attacker get from a compromised pod?

web / api

Web application & API pentest

Manual testing following OWASP WSTG: authentication, authorization, input validation, injection and business logic.

external

External attack surface

What does an attacker see from the outside? Subdomains, exposed services and forgotten systems – mapped with AI, assessed by hand.

linux · ci/cd

Pipeline & supply chain

Build runners, secrets, permissions, container images and dependencies: who can push what into production?

ai

AI applications & pipelines

LLM features following the OWASP Top 10 for LLM Applications, agents with tool access, and the data and model pipeline behind them.

02 / approach

Agents map it. I go in.

AI agents gather in parallel what is publicly discoverable about your systems. Then I take over: targeted, manual and all the way to a verifiable proof. The result is a report your team can act on right away.

The animation follows a real black-box assessment – simplified and anonymised.

agents collecting 1/6
❯ ai-recon start --scope "*.[redacted].de" --agents osint,dns-enum
[*] osint: tech stack · public docs · repos dns-enum: subdomains · records
❯ ai-recon add --agents port-scanning,service-discovery
[*] port-scanning: open ports service-discovery: banners · versions · tech
❯ ai-recon brief --to me && nmap -sV -sC -p 8443 $SUSPECT
[*] findings übernommen · verdächtigen dienst gezielt prüfen
❯ burpsuite --project-file=engagement.burp
[*] auth · inputs · business logic · by hand
❯ python3 poc.py --target svc.[redacted].de
[*] custom proof of concept · reproducible
❯ ai-report draft --findings ./loot && review
[*] agent drafts · every finding verified by hand
network
Proof of concept, reproducible at any time A concrete fix for every finding Help closing the gaps
03 / process

From scoping to retest

  1. 01

    Scoping

    Goals, scope, test type (black, grey or white box) and time window agreed in writing.

  2. 02

    Testing

    AI-assisted reconnaissance, then manual testing. Critical findings are reported immediately, not just in the report.

  3. 03

    Report

    Management summary plus technical findings with reproduction steps, PoC and a concrete fix.

  4. 04

    Retest

    After your fixes I test again and confirm the remediation in writing.

04 / toolbox

Knowing Linux from the inside to attack it from the outside

I have worked with Linux every day since 2006 – from embedded systems in medical and camera technology to build and development servers and production Kubernetes clusters. I know the systems I attack from the inside: permissions, services, configuration and the usual shortcuts in operations. For reconnaissance and reporting I use my own agent workflows; my lab is fully reproducible, and I train regularly on HackTheBox.

offense

  • Burp Suite
  • OWASP ZAP
  • mitmproxy
  • nmap
  • sqlmap
  • ffuf
  • nuclei
  • subfinder
  • httpx
  • katana
  • dnsx
  • dalfox
  • custom exploits & PoCs

ai & agents

  • Claude Code
  • subagents
  • MCP
  • own agents
  • LangGraph
  • Ollama

distributions

  • Debian
  • Ubuntu
  • Red Hat
  • NixOS
  • Talos Linux
  • Kali Linux

operations & hardening

  • systemd
  • auditd
  • OpenSSH
  • nftables
  • WireGuard
  • Tailscale
  • own PKI / CA
  • HashiCorp Vault
  • Ansible
  • Nix Flakes

container & cluster

  • Kubernetes
  • k3s
  • OpenShift
  • Docker
  • Podman
  • Helm
  • ArgoCD
  • RBAC
  • NetworkPolicies
  • Sealed Secrets

embedded linux

  • Yocto / BitBake
  • NXP i.MX6 / i.MX8
  • QEMU
  • Cross-Builds
  • remote debugging & firmware updates

pipeline security

  • Trivy
  • SonarQube
  • Renovate
  • SBOM / SPDX
  • secrets management
Knowledge 05 / ai-security

More than prompt injection

AI applications inherit the weaknesses of classic software and add their own. Here I explain the most important risks for LLM applications and AI pipelines – briefly, clearly and with a link to the in-depth article.

LLM applications

Risks in applications built on language models
  • KnowledgeLLM01

    Prompt injection

    Inputs – typed directly or hidden in documents, web pages and emails – make a model ignore its instructions or follow someone else’s.

    Read more →
  • KnowledgeLLM03

    Excessive agency

    An agent can do more than its task requires: too many tools, too broad permissions, too little human confirmation.

    Read more →
  • KnowledgeLLM05

    Data and model poisoning

    Manipulated training, fine-tuning or embedding data deliberately change how a model behaves.

    Read more →

AI pipelines

From the data to the inference endpoint
  • KnowledgePIPE·03

    Agents & tool access

    MCP servers, tool permissions and automation decide what a manipulated agent can actually do.

    Read more →
  • KnowledgePIPE·02

    Model supply chain

    Provenance and integrity of models, weights and dependencies – including registries and unsafe file formats.

    Read more →
  • KnowledgePIPE·04

    Inference infrastructure

    Model servers and APIs are services like any other: exposed, often weakly isolated, rarely rate-limited.

    Read more →

What would an attacker find in your systems?

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