#VU52680 Improper Authentication in FortiWAN - CVE-2021-26102

Vulnerability identifier: #VU52680

Vulnerability risk: High

CVSSv4.0: 8.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber]

CVE-ID: CVE-2021-26102

CWE-ID: CWE-287

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
FortiWAN
Hardware solutions / Routers & switches, VoIP, GSM, etc

Vendor: Fortinet, Inc

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error in the authentication process. A remote non-authenticated attacker can send a specially crafted HTTP POST request and delete arbitrary files on the system using directory traversal sequences. In particular, deleting specific configuration files will reset the Admin password to its default value.

Successful exploitation of the vulnerability may allow an attacker to gain full access to the affected system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

FortiWAN: before 5.1.1

---

External links
https://fortiguard.com/psirt/FG-IR-21-048

---

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. However, proof of concept for this vulnerability is available.