A vulnerability was identified in Sonatype Nexus Repository 3 in which two blobstore group management REST API endpoints did not correctly enforce the intended authorization check. A user granted only the nexus:blobstores:create permission could invoke these endpoints to convert an existing blobstore into a group blobstore, an action that should require the nexus:blobstores:update permission instead. This could result in unauthorized modification of blobstore configuration without administrator approval. The nexus:blobstores:create permission is a named permission that must be explicitly granted by an administrator; it is not held by default.

Nexus Repository 3 contained a privilege escalation vulnerability in the REST privileges API. An authenticated user with permission to manage privileges could, under certain role configurations, escalate their own access to full administrator by exploiting a type-confusion flaw in the privilege update endpoint.

A user holding a permission to update privilege definitions could modify a wildcard privilege already assigned to their own role to grant broader permissions than they were authorized to hold, including full administrative access, without any additional authorization check or role reassignment.