Remote code execution in QNAP QTS, QuTS hero, and QuTScloud

Published: 2021-09-09

Risk	High
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2021-28816 CVE-2021-34343
CWE-ID	CWE-121
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	QNAP QTS Server applications / File servers (FTP/HTTP) QuTS hero Hardware solutions / Firmware QuTScloud Operating systems & Components / Operating system
Vendor	QNAP Systems, Inc.

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Stack-based buffer overflow

EUVDB-ID: #VU56435

Risk: High

CVSSv4.0: 8.1 [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:U/U:Amber]

CVE-ID: CVE-2021-28816

CWE-ID: CWE-121 - Stack-based buffer overflow

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error. A remote unauthenticated attacker can send a specially crafted request to trigger a stack-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

QNAP QTS: 4.3.2 - 4.5.3.1697 20210611

QuTS hero: before h4.5.4.1771 build 20210825

QuTScloud: before c4.5.6.1755

CPE2.3

External links

https://www.qnap.com/en/security-advisory/qsa-21-33

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.

2) Stack-based buffer overflow

EUVDB-ID: #VU56436