> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/privesc/permissions/linux-permissions-calculator.md).

# Linux Permissions Calculator

Linux permissions calculator for octal and symbolic notation, SUID, SGID, sticky bit, common modes, and privilege escalation triage.

Search an octal mode such as `755`, `644`, `600`, `4755`, or a symbolic mode such as `rwxr-xr-x` to convert permissions and understand impact.

## Permission Finder

<table data-view="cards" data-full-width="true" data-search="true"><thead><tr><th>Octal</th><th>Symbolic</th><th>Meaning</th><th>Typical Use</th><th>Privesc Risk</th></tr></thead><tbody><tr><td><code>000</code></td><td><code>---------</code></td><td>No permissions</td><td>Locked file</td><td>Low</td></tr><tr><td><code>400</code></td><td><code>r--------</code></td><td>Owner read only</td><td>Private key material</td><td>High if readable by wrong owner</td></tr><tr><td><code>600</code></td><td><code>rw-------</code></td><td>Owner read/write</td><td>SSH keys, configs, secrets</td><td>Medium if owner is service account</td></tr><tr><td><code>640</code></td><td><code>rw-r-----</code></td><td>Owner read/write, group read</td><td>Shared service configs</td><td>High if group exposes secrets</td></tr><tr><td><code>644</code></td><td><code>rw-r--r--</code></td><td>Owner write, everyone read</td><td>Public web files</td><td>High for secret files</td></tr><tr><td><code>660</code></td><td><code>rw-rw----</code></td><td>Owner/group read/write</td><td>Team-managed files</td><td>High if group can edit privileged scripts</td></tr><tr><td><code>664</code></td><td><code>rw-rw-r--</code></td><td>Owner/group write, everyone read</td><td>Collaborative files</td><td>Medium to high</td></tr><tr><td><code>666</code></td><td><code>rw-rw-rw-</code></td><td>Everyone read/write</td><td>Rarely appropriate</td><td>Critical for configs, scripts, or auth files</td></tr><tr><td><code>700</code></td><td><code>rwx------</code></td><td>Owner full access only</td><td>Private scripts and directories</td><td>Low if owner is correct</td></tr><tr><td><code>710</code></td><td><code>rwx--x---</code></td><td>Owner full, group execute</td><td>Directory traversal for group</td><td>Medium</td></tr><tr><td><code>750</code></td><td><code>rwxr-x---</code></td><td>Owner full, group read/execute</td><td>Service directories</td><td>Medium if group is broad</td></tr><tr><td><code>755</code></td><td><code>rwxr-xr-x</code></td><td>Owner write, everyone read/execute</td><td>Common binaries and web dirs</td><td>High if writable owner is compromised</td></tr><tr><td><code>770</code></td><td><code>rwxrwx---</code></td><td>Owner/group full access</td><td>Shared admin dirs</td><td>High if group is abusable</td></tr><tr><td><code>775</code></td><td><code>rwxrwxr-x</code></td><td>Owner/group write, everyone read/execute</td><td>Shared web directories</td><td>High for code paths</td></tr><tr><td><code>777</code></td><td><code>rwxrwxrwx</code></td><td>Everyone full access</td><td>Temporary lab files only</td><td>Critical on scripts, dirs, services, web roots</td></tr><tr><td><code>1733</code></td><td><code>rwx-wx-wt</code></td><td>Sticky world-writable directory</td><td>Upload/drop directories</td><td>Medium</td></tr><tr><td><code>1777</code></td><td><code>rwxrwxrwt</code></td><td>World-writable sticky directory</td><td><code>/tmp</code></td><td>Medium; check symlink/race issues</td></tr><tr><td><code>2755</code></td><td><code>rwxr-sr-x</code></td><td>SGID executable</td><td>Run with file group</td><td>High if binary/script is abusable</td></tr><tr><td><code>2775</code></td><td><code>rwxrwsr-x</code></td><td>SGID group-writable directory</td><td>Shared project dirs</td><td>High if group controls executed files</td></tr><tr><td><code>4755</code></td><td><code>rwsr-xr-x</code></td><td>SUID executable</td><td>Runs as file owner</td><td>Critical if owned by root and exploitable</td></tr><tr><td><code>4777</code></td><td><code>rwsrwxrwx</code></td><td>SUID plus world writable</td><td>Severe misconfiguration</td><td>Critical</td></tr><tr><td><code>6755</code></td><td><code>rwsr-sr-x</code></td><td>SUID and SGID executable</td><td>Privileged helper</td><td>Critical if user-controlled behavior exists</td></tr></tbody></table>

## Digit Calculator

| Value | Permission | Symbol |
| ----- | ---------- | ------ |
| 4     | Read       | `r`    |
| 2     | Write      | `w`    |
| 1     | Execute    | `x`    |
| 0     | None       | `-`    |

Add the values for each class:

| Octal Digit | Symbolic | Meaning              |
| ----------- | -------- | -------------------- |
| `0`         | `---`    | No access            |
| `1`         | `--x`    | Execute only         |
| `2`         | `-w-`    | Write only           |
| `3`         | `-wx`    | Write and execute    |
| `4`         | `r--`    | Read only            |
| `5`         | `r-x`    | Read and execute     |
| `6`         | `rw-`    | Read and write       |
| `7`         | `rwx`    | Read, write, execute |

## Special Bits

| Octal Prefix | Bit        | File Meaning            | Directory Meaning                                    |
| ------------ | ---------- | ----------------------- | ---------------------------------------------------- |
| `1`          | Sticky bit | Rare on files           | Users can delete only their own files                |
| `2`          | SGID       | Execute with file group | New files inherit directory group                    |
| `4`          | SUID       | Execute with file owner | Not meaningful for directories on most Linux systems |

## Quick Commands

```bash
stat -c '%A %a %U %G %n' /path/to/file
find / -perm -4000 -type f 2>/dev/null
find / -perm -2000 -type f 2>/dev/null
find / -writable -type d 2>/dev/null
find / -writable -type f 2>/dev/null
```

## Triage Rules

| Finding                                              | Priority |
| ---------------------------------------------------- | -------- |
| Root-owned SUID binary with unusual name or path     | Critical |
| World-writable root-executed script                  | Critical |
| Writable service file or systemd unit                | Critical |
| Writable cron target                                 | Critical |
| World-writable web root                              | High     |
| Group-writable file owned by privileged group        | High     |
| Readable secrets, backups, keys, or database configs | High     |


---

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