A critical vulnerability affecting several models of Zyxel firewalls has been publicly revealed, along with a Metasploit module that exploits it.

Discovered by Rapid 7 researcher Jake Baines and disclosed to Zyxel on April 13, it was fixed by the company with patches released on April 28, but not publicly acknowledged by the company via an associated CVE or security advisory until now.

CVE-2022-30525 is a vulnerability that may be exploited by unauthenticated, remote attackers to inject commands into the OS via the vulnerable firewalls’ administrative HTTP interface, allowing them to modify specific files and execute OS commands.

“If possible, enable automatic firmware updates. Disable WAN access to the administrative web interface of the system,” Baines also advised.

Baines has lamented that Zyxel has patched this vulnerability silently, because this “Tends to only help active attackers, and leaves defenders in the dark about the true risk of newly discovered issues.”

Zyxel says it wasn’t on purpose, but due to “Miscommunication during the disclosure coordination process.”