#VU56436 Stack-based buffer overflow in QNAP Systems, Inc. products - CVE-2021-34343

Vulnerability identifier: #VU56436

Vulnerability 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-2021-34343

CWE-ID: CWE-121

Exploitation vector: Network

Exploit availability: No

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.

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 - 4.3.6.1711 20210621, 4.5.1.1456 20201015 - 4.5.3.1697 20210611

QuTS hero: before h4.5.4.1771 build 20210825

QuTScloud: before c4.5.6.1755

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

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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.