The Tekton Pipelines git resolver is vulnerable to path traversal via the pathInRepo parameter. A tenant with permission to create ResolutionRequests (e.g. by creating TaskRuns or PipelineRuns that use the git resolver) can read arbitrary files from the resolver pod's filesystem, including ServiceAccount tokens. The file contents are returned base64-encoded in resolutionrequest.status.data.
A user with permission to create or update a TaskRun or PipelineRun can crash the Tekton Pipelines controller by setting .spec.taskRef.resolver (or .spec.pipelineRef.resolver) to a string of 31 characters or more, causing a denial of service for all reconciliation.
Tekton Pipelines project provides k8s-style resources for declaring CI/CD-style pipelines. Starting in version 0.35.0, pipelines do not validate child UIDs, which means that a user that has access to create TaskRuns can create their own Tasks that the Pipelines controller will accept as the child Task. While the software stores and validates the PipelineRun's (api version, kind, name, uid) in the child Run's OwnerReference, it only store (api version, kind, …