CITSmart ITSM 9.1.2.22 - LDAP Injection

# Exploit Title: CITSmart ITSM 9.1.2.22 - LDAP Injection
# Google Dork: "citsmart.local"
# Date: 29/12/2020
# Exploit Author: skysbsb
# Vendor Homepage: https://docs.citsmart.com/pt-br/citsmart-platform-9/get-started/about-citsmart/release-notes.html
# Version: < 9.1.2.23
# CVE : CVE-2020-35775

To exploit this flaw it is necessary to have at least one user/password previously registered, because the system checks (ldap bind) the first user returned in the ldap search. However, it returns the last user found in the search to the function that called it (logic error).

So, I call this problem an LDAP injection in conjunction with a programming logic error that allows you to authenticate to CITSmart ITSM with another valid user without needing to know the target user's password.

Affected versions: < 9.1.2.23
Fixed versions: >= 9.1.2.23

Using this LDAP query in the username field of login page you could login with the target_username account without knowing the target account password.

*)(|(sAMAccountName=valid_username)(sAMAccountName=target_username)

You must know at least one username/password because the autenticacaoAD() function at LDAPUtils.java class (package br.com.centralit.citcorpore.integracao.ad) will try to bind with the first user (valid_username) of the query result.

Vendor has acknowledge this vulnerability at ticket 5929 (https://docs.citsmart.com/pt-br/citsmart-platform-9/get-started/about-citsmart/release-notes.html)