Security restrictions bypass in QNAP QTS

1) Improper access control

EUVDB-ID: #VU51880

Risk: Critical

CVSSv3.1: 9 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:U/RC:C]

CVE-ID: N/A

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to improper access restrictions within DLNA server. A remote non-authenticated attacker can connect to the DLNA server on port 8200/tcp and use a specially crafted request to create arbitrary files on the system. The vulnerability can lead to remote code execution.

Mitigation

It is unclear, if the vulnerability was fixed in the latest release of QNAP QTS 4.3.6.1620 Build 20210322, therefore treating it for the moment as unpatched.

Vulnerable software versions

QNAP QTS: 4.3.6.0805 20181228 - 4.3.6.1446 20200929

External links

http://securingsam.com/new-vulnerabilities-allow-complete-takeover/

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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