This High severity org.eclipse.jgit:org.eclipse.jgit Dependency vulnerability was introduced in versions 9.0.0, 9.1.0, 9.2.1, 9.3.0, 9.4.0, and 9.5.0 of Bamboo Data Center and Server. The latest LTS Bamboo 9.6.0 is not impacted by this Vulnerability. 

This org.eclipse.jgit:org.eclipse.jgit Dependency vulnerability, with a CVSS Score of 8.8 and a CVSS Vector of CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H allows an authenticated attacker to expose assets in your environment susceptible to exploitation which has high impact to confidentiality, high impact to integrity, high impact to availability, and requires no user interaction.

Atlassian recommends that Bamboo Data Center and Server customers upgrade to latest version, if you are unable to do so, upgrade your instance to one of the specified supported fixed versions:

See the release notes (https://confluence.atlassian.com/bambooreleases/bamboo-release-notes-1189793869.html). You can download the latest version of Bamboo Data Center and Server from the download center (https://www.atlassian.com/software/bamboo/download-archives).

The National Vulnerability Database provides the following description for this vulnerability: Arbitrary File Overwrite in Eclipse JGit <= 6.6.0

In Eclipse JGit, all versions <= 6.6.0.202305301015-r, a symbolic link present in a specially crafted git repository can be used to write a file to locations outside the working tree when this repository is cloned with JGit to a case-insensitive filesystem, or when a checkout from a clone of such a repository is performed on a case-insensitive filesystem.

This can happen on checkout (DirCacheCheckout), merge (ResolveMerger via its WorkingTreeUpdater), pull (PullCommand using merge), and when applying a patch (PatchApplier). This can be exploited for remote code execution (RCE), for instance if the file written outside the working tree is a git filter that gets executed on a subsequent git command.

The issue occurs only on case-insensitive filesystems, like the default filesystems on Windows and macOS. The user performing the clone or checkout must have the rights to create symbolic links for the problem to occur, and symbolic links must be enabled in the git configuration.

Setting git configuration option core.symlinks = false before checking out avoids the problem.

The issue was fixed in Eclipse JGit version 6.6.1.202309021850-r and 6.7.0.202309050840-r, available via Maven Central https://repo1.maven.org/maven2/org/eclipse/jgit/  and repo.eclipse.org https://repo.eclipse.org/content/repositories/jgit-releases/ . A backport is available in 5.13.3 starting from 5.13.3.202401111512-r.

The JGit maintainers would like to thank RyotaK for finding and reporting this issue.