In Dangerzone, a security vulnerability was detected in the quarantined environment where documents are opened. Vulnerabilities like this are expected and do not compromise the security of Dangerzone. However, in combination with another more serious vulnerability (also called container escape), a malicious document may be able to breach the security of Dangerzone. We are not aware of any container escapes that affect Dangerzone.
To reduce that risk, you are strongly advised to update Dangerzone to the latest version.
Summary
A series of vulnerabilities in gst-plugins-base (CVE-2024-47538, CVE-2024-47607 and CVE-2024-47615) affects the contained environment where the document rendering takes place.
If one attempts to convert a malicious file with an embedded Vorbis or Opus media elements, arbitrary code may run within that environment. Such files look like regular Office documents, which means that you cannot avoid a specific extension. Other programs that open Office documents, such as LibreOffice, are also affected, unless the system has been upgraded in the meantime.
How does this impact me?
The expectation is that malicious code will run in a container without Internet access, meaning that it won't be able to infect the rest of the system.
What do I need to do?
You are strongly advised to update your Dangerzone installation to 0.8.1 as soon as possible.
This release includes various new features, stability improvements and security fixes. If you are on a Mac or PC you should additionally ensure that the Docker Desktop application is up to date. In addition to the changes specific to this release, we want to note that you can now use Dangerzone on the Tails live system. You can read the announcement on their blog, or read the documentation about it.
The highlights are:
The second phase of the conversion (pixels to PDF) now happens on the host.
Instead of first grabbing all of the pixel data from the first container, storing them on disk, and then reconstructing the PDF on a second container, Dangerzone now immediately reconstructs the PDF on the host, while the doc to pixels conversion is still running on the first container. This architectural change removes a class of problems we had in the past:
Issues with temporary directories and their permissions.
Out of space issues caused by documents with lots of pages (mainly impacted Qubes users).
SELinux issues due to relabeling mounted files.
Mounting files to Docker containers, prevented by security policies in Windows/macOS.
Not being able to run with user ID other than 1000.
If at some point in time you were affected by the above, we suggest giving this version a shot. The sanitization is no less safe, since the boundaries between the sandbox and the host are still respected (#625).
Installation and execution errors are now caught and displayed in the interface, which should make debugging easier (#193)
The macOS entitlements have been revisited, following our security audit. We have now removed unneeded privileges (#638)
We now always use our own seccomp policy as a default (#908)
Platform support updates
This release is the last one that will support Ubuntu Focal (20.04).
Ubuntu Focal is nearing its end of life date, due in April 2nd, 2025 (#965). We urge you to update to a newer Ubuntu version in order to get security updates.
This release includes a patch for Docker Desktop, and security updates. If you are on a Mac or PC you should additionally ensure that the Docker Desktop application is up to date. To install, follow the links in our downloads page.
The two changes in this release are:
Make Dangerzone work with fresh Docker Desktop installations
This release mainly addresses an issue with new Docker Desktop installations on Windows and Mac OS. Users who have done a fresh installation of Docker Desktop 4.30.0 or greater (released on August 29th), have reported that Dangerzone fails conversions with the following error message:
Unknown Error Code '125'
This error message is attributed to a new way that Docker Desktop stores and references container images, which broke some Dangerzone expectations. With this release, we enable Dangerzone to work both with older Docker Deskop installations and newer ones.
Update the software in our container image
As in every release, we rebuild our container image to get the latest security updates.
For a full list of the changes, see our changelog.
One of the oft-repeated sound bites of computer security advice is: “Don’t open random attachments from strangers.” If you are a journalist, however, opening attachments and documents is part of your job description. Since journalists already have a lot of security threats to worry about in dealing with sources, the safe opening of documents should not be one of them. Dangerzone was developed to solve this problem. It lets you open suspicious documents with confidence and gets out of your way.
For the past few months, members of the Dangerzone team and the gVisor project collaborated on significantly improving the security properties of Dangerzone. We’re excited to announce that as of version 0.7.0, Dangerzone uses gVisor to secure its document conversion process. It is already trusted by Google and others to secure cloud products, scan Gmail attachments for viruses, etc.
Welcome to the official Dangerzone blog. We will mainly cover:
release announcements
security updates (e.g., about code audits or vulnerabilities)
articles related to document sanitization and Dangerzone's inner workings.
You can follow the blog in your feed reader of choice. If you have thoughts on topics to cover (or would like to draft a post yourself), please don't hesitate to get in touch via our discussion forums.
Thank you for being part of the Dangerzone community!