Patching for Dirty Cow on Debian, Red Hat, Ubuntu, CentOS

“Dirty Cow” is the common name given to Linux vulnerability CVE-2016-5195. It is a “privilege escalation” that allows a non-root user to gain root access on a system. An attacker must have system access first, as a normal user. Then they use the bug to obtain root rights. It is dangerous and should be patched.

The Linux kernel itself was fixed in October 2016. Since then, Linux vendors have all released patches. Many Internet articles suggest addressing the bug by doing a general system update. While that might be fine for a test machine or Linux desktop, it isn’t ideal for a production server. This article describes how to fix the bug in the least invasive way possible – by updating the kernel only. Continue reading

Debian 7 to Debian 8 Migration Gotchas

Debian 8 (jessie) was released in April 2015, ten months ago at the time of writing. Some sites will have upgraded by now, and others might be considering the move. This article provides a list of issues encountered after upgrading several servers from Debian 7 (wheezy) to Debian 8. These are system administration issues in the most part, though some might also be of interest to application support staff. Continue reading

Raspberry Pi Basic Configuration

The Raspberry Pi is a small Linux computer designed to help children learn programming. Being a full Linux System, it can also be used as a server or as the basis for various projects.

Here are some adjustments you might want to make to a new Raspberry Pi. The examples refer to a Raspberry Pi Model “B” bought from UK distributors New IT in February 2013. But they are pretty universal. Continue reading

Upgrading the Sheevaplug to Debian 6 Squeeze

The Sheevaplug is is a very small computer made by Globalscale. It is designed to offer standard computing functions in a very small space. Consuming just a few watts of power, the Sheevaplug makes a good home server, with applications ranging from network storage to web hosting and home security.

This article explains how to upgrade a Sheevaplug to Debian 6 using a pre-built image available from New IT. It is a quick and simple procedure, requiring less technical knowledge than, for example, installing Debian from scratch. Continue reading