Vulnerability identifier: #VU56818

Vulnerability risk: High

CVSSv3.1: 7.1 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-40847

CWE-ID: CWE-94

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
R6400v2
Hardware solutions / Routers for home users
R6700
Hardware solutions / Routers for home users
R6900
Hardware solutions / Routers for home users
R6900P
Hardware solutions / Routers for home users
R7000
Hardware solutions / Routers for home users
R7000P
Hardware solutions / Routers for home users
R7850
Hardware solutions / Routers for home users
R7900
Hardware solutions / Routers for home users
R8000
Hardware solutions / Routers for home users
RS400
Hardware solutions / Routers for home users
R6700v3
Hardware solutions / Routers & switches, VoIP, GSM, etc

Vendor:

Description

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

The vulnerability exists due to improper input validation in the circled update daemon. A remote attacker can 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

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External links
http://blog.grimm-co.com/2021/09/mama-always-told-me-not-to-trust.html
http://kb.netgear.com/000064039/Security-Advisory-for-Remote-Code-Execution-on-Some-Routers-PSV-2021-0204

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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.