Safety researchers have launched technical particulars and a proof-of-concept (PoC) exploit for a vital vulnerability patched final week in Fortinet’s FortiClient Enterprise Administration Server (FortiClient EMS), an endpoint security administration answer. The vulnerability, tracked as CVE-2023-48788, was reported to Fortinet as a zero-day by the UK Nationwide Cyber Safety Centre (NCSC) and was actively exploited within the wild on the time of the patch, however probably in very focused assaults. The supply of the brand new PoC, regardless that not weaponized, may allow wider exploitation and simpler adoption by extra attacker teams.
The flaw is the results of improper sanitization of components in an SQL command, which might be exploited in an SQL injection state of affairs to execute unauthorized code or instructions on the FortiClient EMS. Prospects are suggested to improve to model 7.0.11 or above for the 7.0.x collection and to model 7.2.3 or above for the 7.2.x collection.
Fortinet vulnerability trivial to take advantage of
FortiClient EMS is the central server part that’s used to handle endpoints working FortiClient. In response to researchers with penetration testing agency Horizon3.ai, who reconstructed the vulnerability, it’s in a part referred to as FCTDas.exe, or the Data Entry Server, which communicates with Microsoft SQL Server database to retailer info acquired from endpoints.
Endpoints which have FortiClient put in talk with a part of the EMS referred to as FmcDaemon.exe over port 8013 utilizing a customized text-based protocol that’s then encrypted with TLS for cover. FmcDaemon.exe then passes info to FCTDas.exe within the type of SQL queries which are then executed towards the database.
The researchers managed to construct a Python script to work together with FmcDaemon.exe and ship a easy message to replace the FCTUID adopted by an SQL injection payload to set off a 10-second sleep. They then noticed that the payload was handed to FCTDas.exe, subsequently confirming the vulnerability.
“To show this SQL injection vulnerability into distant code execution we used the built-in xp_cmdshell performance of Microsoft SQL Server,” the researchers mentioned of their technical write-up. “Initially, the database was not configured to run the xp_cmdshell command. Nonetheless, it was trivially enabled with a number of different SQL statements.”
The researchers deliberately left the xp_cmdshell code execution half out of the PoC exploit, so it can’t be abused immediately with out modification. Nonetheless, the xp_cmdshell method is well-known and has been used to assault Microsoft SQL Server databases earlier than, which means it’s not laborious to implement that half.
Fortinet flaws are enticing to attackers
In February, Fortinet patched one other vital distant code execution vulnerability within the SSL VPN service of the FortiOS working system used on its home equipment. That vulnerability, tracked as CVE-2024-21762, additionally got here with a warning that it was probably exploited within the wild. The corporate additionally warned that Chinese language cyberespionage teams exploited N-day FortiOS vulnerabilities up to now to focus on vital infrastructure organizations.
