Path traversal in Reposilite javadoc file expansion (arbitrary file creation/overwrite) (`GHSL-2024-073`)

QFinch assessment

Reposilite v3.5.10 is affected by an Arbitrary File Upload vulnerability via path traversal in expanding of Javadoc archives.

Potential impact

If the archive is taken from an untrusted source, such as Maven Central or JitPack for example, an attacker can craft a special archive to overwrite any local file on Reposilite instance. This could lead to remote code execution, for example by placing a new plugin into the '$workspace$/plugins' directory. Alternatively, an attacker can overwrite the content of any other package. Note that the attacker can use its own malicious package from Maven Central to overwrite any other package on Reposilite.

Technical context

Reposilite provides support for JavaDocs files, which are archives that contain documentation for artifacts. Specifically, JavadocEndpoints.kt controller allows to expand the javadoc archive into the server's file system and return its content. The problem is in the way how the archives are expanded, specifically how the new filename is created: JavadocContainerService.ktL127-L136 The file.name taken from the archive can contain path traversal characters, such as '/../../../anything.txt', so the resulting extraction path can be outside the target directory.