Insecure DLL loading in Fortinet FortiClient

1) Insecure DLL loading

EUVDB-ID: #VU18513

Risk: Medium

CVSSv4.0: 4.8 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-5589

CWE-ID: CWE-427 - Uncontrolled Search Path Element

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to the application loads DLL libraries in an insecure manner during installation, when FortiClientOnlineInstaller.exe is executed. A remote attacker can place a specially crafted .dll file on a remote SMB fileshare, trick the victim into executing the FortiClientOnlineInstaller.exe file from the share and execute arbitrary code on victim's system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Fortinet FortiClient for Windows: 6.0.0 - 6.0.5

CPE2.3

• cpe:2.3:a:fortinet:fortinet_forticlient:6.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:fortinet:fortinet_forticlient:6.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:fortinet:fortinet_forticlient:6.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:fortinet:fortinet_forticlient:6.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:fortinet:fortinet_forticlient:6.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:fortinet:fortinet_forticlient:6.0.5:*:*:*:*:*:*:*

External links

https://fortiguard.com/psirt/FG-IR-19-060

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.