Bundler 1.16.0 through 2.2.9 and 2.2.11 through 2.2.16 sometimes chooses a dependency source based on the highest gem version number, which means that a rogue gem found at a public source may be chosen, even if the intended choice was a private gem that is a dependency of another private gem that is explicitly depended on by the application. NOTE: it is not correct to use CVE-2021-24105 for every "Dependency Confusion" issue in every product.

<p>Depending on configuration of various package managers it is possible for an attacker to insert a malicious package into a package manager's repository which can be retrieved and used during development, build, and release processes. This insertion could lead to remote code execution. We believe this vulnerability affects multiple package managers across multiple languages, including but not limited to: Python/pip, .NET/NuGet, Java/Maven, JavaScript/npm.</p> <p><strong>Attack scenarios</strong></p> <p>An attacker could take advantage of this ecosystem-wide issue to cause harm in a variety of ways. The original attack scenarios were discovered by Alex Birsan and are detailed in their whitepaper, <a href="https://medium.com/@alex.birsan/dependency-confusion-4a5d60fec610">Dependency Confusion: How I Hacked Into Apple, Microsoft and Dozens of Other Companies</a>.</p> <ul> <li><p>With basic knowledge of the target ecosystems, an attacker could create an empty shell for a package and ins…