Backdoor to be Found in Bootstrap-sass Ruby Gem

Backdoor has been added to the, published March 26 in the RubyGems repository and issue is resolved in release, proposed on April 3rd
05 April 2019   731

Backdoor (CVE-2019-10842) was detected in the popular Ruby-library bootstrap-sass (Bootstrap 3 option with Sass support), which has about 28 million downloads, allowing attackers to execute their code on servers running projects using bootstrap-sass . The backdoor has been added to release, published March 26 in the RubyGems repository. The issue is resolved in release, proposed on April 3rd.

The backdoor was hiddenly added to the lib/active-controller/middleware.rb, in which the code for calling eval appeared with the value passed through the cookie"___ cfduid =". For an attack, it was enough to send a request to the server, setting thecookie "___cfduid" and pass as an argument the commands encoded in Base64 format. The name of the cookie "___cfduid" was chosen for camouflage under thecookie "__cfduid", set by CDN Cloudflare and characterized by the presence of two underscores instead of three.

It is noteworthy that the malicious code was published only in the final package published in the RubyGems repository, but was not included in the source code in the Git repository. The source code of the library remained correct and did not arouse suspicion among developers, which underscores the importance of using repeatable builds and implementing a process to verify the compliance of published packages with reference sources. Apparently, the attack was carried out through the seizure of the account parameters to RubyGems from one of the two library maintainers (officially the leakage of account data has not yet been confirmed).

The attackers showed prudence and built the backdoor not into the latest 3.4.x branch, the latest release of which has more than 217,000 downloads, but as an update for the previous 3.2.x branch, relying on the fact that corrective update of dependency will not cause suspicion. A rough estimate of the 1670 repositories on GitHub use bootstrap-sass as a dependency and applications associated with these repositories can potentially be compromised. Developers are advised to trace the use of the bootstrap-sass library among indirect dependencies and check whether the automatic upgrade to the backdoor version has been performed. Judging by the statistics of the RubyGems package, the backdoor package was downloaded about 1,500 times.

Information about a possible backdoor was published in the bug tracking system a few hours after placing the problematic release, after which the maintainers removed the problematic release from RubyGems about an hour later and changed their login passwords, but did not take into account that the removed versions could remain for several days on the mirrors. On April 3, an additional release was created, completely analogous to version, which made it possible to get rid of the version with backdoor without switching to a new branch 3.4.

GitHub to Launch Sponrship System

GitHub does not charge fees, and the first year will cover the costs of processing payments
24 May 2019   277

System called GitHub Sponsors is launched to provide financial support for open source projects. The new service provides a new form of participation in the development of projects - if the user does not have the opportunity to help in the development, he or she can join the projects of interest as a sponsor and help through funding specific developers, maintainers, designers, documentation authors, testers and other participants involved in the project.

Using the sponsorship system, any GitHub user can monthly transfer fixed amounts to open source developers who have registered with the service as members willing to receive financial support (the number of participants is limited at the time the service is tested). Sponsored members can define support levels and associated sponsor privileges, such as exceptional bug fixes. The possibility of organizing financing not only individual participants, but also the groups of developers involved in the work on the project is being considered.

Unlike other co-financing sites, GitHub does not charge fees, and the first year will cover the costs of processing payments. In the future, the introduction of fees for processing payments is not excluded. To support the service, a special fund called GitHub Sponsors Matching Fund has been created, which will deal with the distribution of financial flows.