Ubuntu Linux is one of the most popular Linux distributions in use today, making its users an attractive target for hackers. In an attack that was officially confirmed on July 15, Canonical, the lead commercial vendor behind Ubuntu Linux, revealed that its Ubuntu Forums user community was hacked, and the attacker gained unauthorized access to a database of 2 million users.
Although an attacker was able to gain access to the user database, the access was somewhat limited and didn't directly expose any valid user passwords, according to Canonical CEO Jane Silber. "We know the attacker was not able to gain access to any Ubuntu code repository or update mechanism," Silber wrote in a blog post. "We know the attacker was not able to gain access to valid user passwords."
What the attacker was able to access was the ability to read any information in the user forums database tables. However, Canonical's analysis is that the attacker only accessed the user table in the database, Silber said.
With the database access, the attacker was able to download usernames, email addresses and IP addresses for 2 million users. The Ubuntu user forums make use of the Ubuntu single sign-on approach, which did not store user passwords in the forums database. Rather, the password credentials for users were present in the user database as random strings of data.
Canonical determined the root cause of the Ubuntu forums breach to be a known SQL injection vulnerability in the Forumrunner add-on for the vBulletin forum software. Though Canonical is constantly updating its Ubuntu software, apparently the organization had neglected to update Forumrunner and vBulletin to be up-to-date with the latest patches.
So to recap, information on 2 million Ubuntu users was breached, not from an exotic zero-day attack, but from a known SQL injection vulnerability that Canonical should have patched. Certainly, Canonical isn't unique here, as more often than not, in many breaches, it is known, already-patched vulnerabilities that are identified as a root cause.
To its credit though, Canonical didn't have easily readable passwords stored in its forums user database. That doesn't mean that there isn't a risk, as attackers now have a list of 2 million Ubuntu users, complete with their email addresses and IP addresses that could perhaps be used for phishing or other wrongdoing.
As a fix for the breach, Canonical has patched vBulletin and put in place a Web application firewall (WAF)—both actions that should have been present prior to the breach. Canonical is using the open-source ModSecurity WAF, which can be configured and used to limit the risks of potential SQL injection attacks.
Certainly, Canonical is not the first (and won't be the last) Linux organization that is the victim of a breach. Back in 2011, the Linux Foundation was the victim of a security breach that exposed passwords and email addresses. In February, attackers breached the user forums for the popular Linux Mint distribution.
In the modern era, the simple truth is that any unpatched or misconfigured system, be it Linux or otherwise, represents an easy target for an attacker to breach. It is incumbent on all operating system vendors to be forever vigilant in fully patching systems, ensuring correct permission configuration and making use of additional security layers, such as a WAF, to protect themselves and their users.
Sean Michael Kerner is a senior editor at eWEEK and InternetNews.com. Follow him on Twitter @TechJournalist.