fix(security): Security Fix for HTML injection to Stored XSS - huntr.dev

[huntr-helper]

https://huntr.dev/users/Mik317 has fixed the HTML injection to Stored XSS vulnerability 🔨. Mik317 has been awarded $25 for fixing the vulnerability through the huntr bug bounty program 💵. Think you could fix a vulnerability like this?

Get involved at https://huntr.dev/

Q | A
Version Affected | ALL
Bug Fix | YES
Original Pull Request | 418sec#1
Vulnerability README | https://github.com/418sec/huntr/blob/master/bounties/other/monica/1/README.md

User Comments:

Bounty URL: https://www.huntr.dev/bounties/1-other-monica/

⚙️ Description *

The monica CMS is vulnerable against stored-XSS which occurred when creating a new journal which was then shown
😄

💻 Technical Description *

I added a server-side strict check to html encode in entities every HTML tag which is inserted inside the post body aka entry. I used the htmlentities() to accomplish this task, and I modified also the edit action in order to avoid bypasses 😄

🐛 Proof of Concept (PoC) *

1. Install the CMS and start the server
2. Go on http://127.0.0.1:8000/journal and click the Add a journal entry button
3. Add as title and content the following value: <img src="x" onerror=alert(1)>
4. Save
5. An XSS is popped in the Journal list page

🔥 Proof of Fix (PoF) *

Same steps with fixed version:

👍 User Acceptance Testing (UAT)

All OK and tested for bypasses 👍

[CLAassistant]

All committers have signed the CLA.

[asbiin]

Thank you @Mik317
However, I will that another way, because it can affect current data.

[asbiin]

Superseeded by #4451

[github-actions]

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