malerisch.net

Back in 2015, I have published a blog post titled " Pwning a thin client in less two minutes " which attracted a lot of curiosity from the Internet and which was also featured in the  HACKADAY  blog. Today, together with Vincent Hutsebaut ( @vhutsebaut ), we are releasing a further technique to pwn the same thin client and get a root shell without authentication, in less than one minute! The attack detailed below is a typical kiosk attack which consists in a local privilege escalation which affects different versions of HP Thin Pro OS (HP ThinPro 4.4, HP ThinPro 5.0, HP ThinPro 5.1, HP ThinPro 5.2, HP ThinPro 5.2.1, HP ThinPro 6.0, HP ThinPro 6.1). The vulnerability (CVE-2016-2246) has been patched by HP and a technical bulletin has been published . HP stated that they have fixed the issue before our report was sent to them and were on the way to publish a security bulletin when we contacted them. Since the patch is out, let's dive into the vulnerability, which i

Have you ever encountered a zero client or a thin client? It looks something like this... If yes, keep reading below, if not, then if you encounter one, you know what you can do if you read below... The model above is a T520, produced by HP - this model and other similar models are typically employed to support a medium/large VDI (Virtual Desktop Infrastructure) enterprise. These clients run a Linux-based HP ThinPro OS by default and I had a chance to play with image version T6X44017 in particular, which is fun to play with it, since you can get a root shell in a very short time without knowing any password... Normally, HP ThinPro OS interface is configured in a kiosk mode, as the concept of a thin/zero client is based on using a thick client to connect to another resource. For this purpose, a standard user does not need to authenticate to the thin client per se and would just need to perform a connection - e.g. VMware Horizon View. The user will eventually authenticat