CVE-2021-20853 Command injection in ELECOM LAN routers

Medium 6.8 Published 1 Dec 2021 Updated 3 Aug 2024

An administrator on ELECOM LAN routers can execute arbitrary OS commands, posing a risk of full device compromise.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-20853?

CVE-2021-20853 is a medium-severity command injection vulnerability in ELECOM LAN routers, published on 1 Dec 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

ELECOM LAN routers (WRH-733GBK firmware v1.02.9 and prior and WRH-733GWH firmware v1.02.9 and prior) allows a network-adjacent attacker with an administrator privilege to execute arbitrary OS commands via unspecified vectors.

Weakness: CWE-78

Which versions are affected by CVE-2021-20853?

It affects 2 products.

Products include Elecom Wrh-733gbk Firmware, Elecom Wrh-733gwh Firmware.

How do I fix CVE-2021-20853?

No fix has been published for CVE-2021-20853 yet. Limit exposure of the affected software until one is available.

Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.

Is CVE-2021-20853 being exploited?

There is no known exploitation of CVE-2021-20853 in the wild and no public exploit code.

Sources

Also known as GHSA-mjp9-fwhq-c9rm.