#VU60349 Improper validation of integrity check value in TN-5900 - CVE-2021-46559

Vulnerability identifier: #VU60349

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-46559

CWE-ID: CWE-354

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
TN-5900
Hardware solutions / Routers & switches, VoIP, GSM, etc

Vendor: Moxa

Description
The vulnerability allows a remote attacker to bypass integrity checks.

The vulnerability exists due to a weak algorithm. A remote authenticated attacker can upload abritrary code in a crafted firmware image simply by replacing a CRC value in the image header.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

TN-5900: 3.1.0

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External links
https://www.moxa.com/en/support/product-support/security-advisory/tn-5900-secure-routers-vulnerabilities

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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