Barracuda Email Security Gateway Appliance (ESG) Vulnerability

It's basically an infrastructure remote code exploit (RCE) by just sending an email to an organisation.

> ACTION NOTICE: Impacted ESG appliances must be immediately replaced regardless of patch version level. If you have not replaced your appliance after receiving notice in your UI, contact support now (support@barracuda.com).

CVE max score

https://nvd.nist.gov/vuln/detail/CVE-2023-2868

Looks like the vulnerability is rooted in Perl.