Security audit
Security checks for vulnerabilities and agentic risk
This is a real VPS deployment guide, but it asks for broad permanent root-level server changes that could expose or break a server if run as written.
Review carefully before installing. Use only on a fresh or dedicated VPS, require explicit confirmation before SSH, firewall, Nginx, or destructive changes, replace curl-to-shell Docker installation with a verified package workflow, use a dedicated deploy public key instead of copying root authorized_keys, avoid unrestricted passwordless sudo, and back up Nginx configs before changes.
SKILL.md:91Unverified Remote Script Executed with Root Privileges
SKILL.md:56Deploy Account Receives Multiple Unrestricted Root-Equivalent Privileges
SKILL.md:64Root SSH Authorization Is Duplicated into a Root-Equivalent Deployment Account
SKILL.md:184Unvalidated Deployment Values Are Interpolated into Privileged Shell Commands and Configuration Paths
Creating /home/deploy/.ssh as part of an automated flow is not inherently dangerous, but in this context it is directly tied to populating the directory with root's authorized_keys. That workflow expands access to a new account without explicit user-controlled key enrollment and can unintentionally propagate privileged access.
# Copy root's authorized_keys to deploy user
mkdir -p /home/deploy/.ssh
cp ~/.ssh/authorized_keys /home/deploy/.ssh/ 2>/dev/null || true
chown -R deploy:deploy /home/deploy/.ssh
chmod 700 /home/deploy/.ssh
chmod 600 /home/deploy/.ssh/authorized_keys 2>/dev/null || true
Creating /home/deploy/.ssh as part of an automated flow is not inherently dangerous, but in this context it is directly tied to populating the directory with root's authorized_keys. That workflow expands access to a new account without explicit user-controlled key enrollment and can unintentionally propagate privileged access.
# Copy root's authorized_keys to deploy user
mkdir -p /home/deploy/.ssh
cp ~/.ssh/authorized_keys /home/deploy/.ssh/ 2>/dev/null || true
chown -R deploy:deploy /home/deploy/.ssh
chmod 700 /home/deploy/.ssh
chmod 600 /home/deploy/.ssh/authorized_keys 2>/dev/null || true
Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
cp ~/.ssh/authorized_keys /home/deploy/.ssh/ 2>/dev/null || true
chown -R deploy:deploy /home/deploy/.ssh
chmod 700 /home/deploy/.ssh
chmod 600 /home/deploy/.ssh/authorized_keys 2>/dev/null || true
# Harden SSH config
sed -i 's/#\?PermitRootLogin.*/PermitRootLogin no/' /etc/ssh/sshd_config
Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
cp ~/.ssh/authorized_keys /home/deploy/.ssh/ 2>/dev/null || true
chown -R deploy:deploy /home/deploy/.ssh
chmod 700 /home/deploy/.ssh
chmod 600 /home/deploy/.ssh/authorized_keys 2>/dev/null || true
# Harden SSH config
sed -i 's/#\?PermitRootLogin.*/PermitRootLogin no/' /etc/ssh/sshd_config
Piping downloaded content directly into sh is a classic dangerous command-chaining pattern because it combines retrieval and execution in one step, eliminating validation checkpoints. Since this occurs during privileged server setup, any malicious or corrupted response becomes immediate root command execution.
curl -fsSL https://get.docker.com | sh
usermod -aG docker deploy
Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
restart: unless-stopped
ports:
- "127.0.0.1:${APP_PORT:-3000}:${APP_PORT:-3000}"
env_file: .env
healthcheck:
test: ["CMD", "curl", "-f", "http://localhost:${APP_PORT:-3000}/"]
interval: 30s
The command unconditionally removes /etc/nginx/sites-enabled/default, which is a destructive host-level change. In context, this deployment skill may be used on non-fresh servers, so deleting an existing site definition without backup or confirmation can break unrelated services or remove an intentionally configured default vhost.
EOF
ln -sf /etc/nginx/sites-available/ /etc/nginx/sites-enabled/ rm -f /etc/nginx/sites-enabled/default nginx -t && systemctl reload nginx
The skill metadata includes broad trigger phrases like 'set up my server' and 'deploy to production', which can cause the skill to activate for requests that may not actually intend full VPS reconfiguration. Because this skill performs sensitive server-hardening and deployment actions, accidental invocation materially increases the risk of destructive or over-privileged operations.
Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.
## Prerequisites
- SSH access to a VPS (IP address + root or sudo credentials)
- A domain pointed to the VPS IP (for SSL — can skip SSL if no domain)
- The app must have a Dockerfile or be deployable via Docker
The skill grants the 'deploy' user passwordless sudo for all commands via NOPASSWD:ALL, which creates a permanently over-privileged account. If that account or its SSH key is compromised, an attacker gains immediate full-root control of the server without additional barriers.
adduser --disabled-password --gecos "" deploy
usermod -aG sudo docker deploy
echo "deploy ALL=(ALL) NOPASSWD:ALL" >> /etc/sudoers.d/deploy
Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.
mkdir -p /home/deploy/.ssh
cp ~/.ssh/authorized_keys /home/deploy/.ssh/ 2>/dev/null || true
chown -R deploy:deploy /home/deploy/.ssh
chmod 700 /home/deploy/.ssh
chmod 600 /home/deploy/.ssh/authorized_keys 2>/dev/null || true
# Harden SSH config
Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.
cp ~/.ssh/authorized_keys /home/deploy/.ssh/ 2>/dev/null || true
chown -R deploy:deploy /home/deploy/.ssh
chmod 700 /home/deploy/.ssh
chmod 600 /home/deploy/.ssh/authorized_keys 2>/dev/null || true
# Harden SSH config
sed -i 's/#\?PermitRootLogin.*/PermitRootLogin no/' /etc/ssh/sshd_config
The skill's safety rules explicitly require backing up existing Nginx configs before overwriting, but the operational steps write a new site config, replace the enabled symlink, and remove the default site without any backup. In a production deployment skill, this can break an existing web stack or cause accidental service disruption, especially if run on a server already hosting applications.
Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
## Safety Rules
- **NEVER** disable the firewall without asking
- **NEVER** expose database ports to the internet
- **ALWAYS** verify SSH access with the deploy user BEFORE disabling root login
- **ALWAYS** back up existing Nginx configs before overwriting
The 'When to Use' section contains ambiguous phrases such as 'go to production' and 'set up my server' without enough scoping to a new VPS or dedicated host. In context, that ambiguity is risky because the skill includes firewall, SSH, Nginx, and Docker changes that may be inappropriate for shared or pre-existing environments.
Fetching and executing a remote install script with curl directly into sh removes an opportunity for inspection, integrity verification, or pinning to a trusted package source. In a root-level VPS setup flow, compromise of the upstream script, transport path, or unexpected script changes would immediately grant arbitrary code execution as root.
curl -fsSL https://get.docker.com | sh
usermod -aG docker deploy
No suspicious patterns detected.