ubuntu – PwnDefend

Cyber Essentials for Ubuntu Servers

I thought about doing a step by step bash script or CLI walkthrough but decided to go with the high levels steps. If we wanted to ensure our Linux servers are configured in alignment with Cyber Essentials what are the main areas we need to consider? For this I’m using Ubuntu Server as a base, I’ve not gone through every line in the standard but these should be in line with the 5 areas and fit within the Cyber Essentials theme. As always there are many ways to skin a cat! (don’t skin cats they are frens!). Anyway hope this is useful.

Defense

Creating a honeypot for CVE-2021-41773 (Path Traversal and RCE)

A path traversal vulnerability and exploit just dropped in the wild for a specific version of Apache (Apache/2.4.49). This vulnerability allows an unauthenticated attacker to execute a path traversal attack (and now shown RCE if MOD_CGI is enabled) to read files outside of the virtual directory path bounds. This only affects a single version of Apache, there’s a fair few of these online, however it’s very unlikely all are vulnerable. The vulnerability requires specific permissions to be configured.