#VU67062 Format string error in ZyXEL Communications Corp. products - CVE-2022-34747

Vulnerability identifier: #VU67062

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-2022-34747

CWE-ID: CWE-134

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
NAS326
Hardware solutions / Routers for home users
NAS540
Hardware solutions / Routers for home users
NAS542
Hardware solutions / Routers for home users

Vendor: ZyXEL Communications Corp.

Description

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

The vulnerability exists due to a format string error. A remote attacker can use a specially crafted UDP packet 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

NAS326: 5.21(AAZF.11)C0

NAS540: 5.21(AATB.8)C0

NAS542: 5.21(ABAG.8)C0

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External links
https://www.zyxel.com/support/Zyxel-security-advisory-for-format-string-vulnerability-in-NAS.shtml

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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.