The Federal Bureau of Investigation has sent out a security alert warning that threat actors are abusing misconfigured SonarQube applications to access and steal source code repositories from US government agencies and private businesses.
Intrusions have taken place since at least April 2020, the FBI said in an alert sent out last month and made public this week on its website.
The alert specifically warns owners of SonarQube, a web-based application that companies integrate into their software build chains to test source code and discover security flaws before rolling out code and applications into production environments.
SonarQube apps are installed on web servers and connected to source code hosting systems like BitBucket, GitHub, or GitLab accounts, or Azure DevOps systems.
But the FBI says that some companies have left these systems unprotected, running on their default configuration (on port 9000) with default admin credentials (admin/admin).
FBI officials say that threat actors have abused these misconfigurations to access SonarQube instances, pivot to the connected source code repositories, and then access and steal proprietary or private/sensitive applications.
Officials provided two examples of past incidents:
"In August 2020, unknown threat actors leaked internal data from two organizations through a public lifecycle repository tool. The stolen data was sourced from SonarQube instances that used default port settings and admin credentials running on the affected organizations' networks.
"This activity is similar toa previous data leak in July 2020, in which an identified cyber actor exfiltrated proprietary source code from enterprises throughpoorly secured SonarQube instances and published the exfiltrated source codeon a self-hosted public repository."
Forgot problem resurfaces in 2020
The FBI alert touches on a little known issue among software developers and security researchers.
While the cyber-security industry has often warned about the dangers of leaving MongoDB or Elasticsearch databases exposed online without passwords, SonarQube has slipped through the cracks.
However, some security researchers have been warning about the dangers of leaving SonarQube applications exposed online with default credentials since as far back as May 2018.
At the time, data breach hunter Bob Diachenko warned that about 30% to 40% of all the ~3,000 SonarQube instances available online at the time had no password or authentication mechanism enabled.
This year, a Swiss security researcher named Till Kottmann has also raised the same issue of misconfigured SonarQube instances. Throughout the year, Kottmann has gathered source code from tens of tech companies in a public portal, and many of these came from SonarQube applications.
"Most people seem to change absolutely none of the settings, which are actually properly explained in the setup guide from SonarQube," Kottmann told ZDNet.
"I don't know the current number of exposed SonarQube instances, but I doubt it changed much. I would guess it's still far over 1,000 servers (that are indexed by Shodan) which are 'vulnerable' by either requiring no auth or leaving default creds," he said.
To prevent leaks like these, the FBI alert lists a series of steps that companies can take to protect their SonarQube servers, starting with altering the app's default configuration and credentials and then using firewalls to prevent unauthorized access to the app from unauthorized users.
Update on December 14, 2020: SonarQube has also made modifications of its own. Starting with v8.6, released in December 2020, the app is now warning admins if they left the admin account enabled with a default or no password.