Relative path traversal vulnerability in Apache Camel Google Storage component.
This issue affects Apache Camel: from 4.0.0 before 4.14.9, from 4.15.0 before 4.18.4, from 4.19.0 before 4.22.0.
The camel-google-storage consumer downloads Google Cloud Storage objects to the local filesystem when the downloadFileName option is set. That option is documented as a folder or a filename, and when its value contains no expression token the consumer builds the local destination by appending the object name to it: evaluateFileExpression sets the Exchange file-name header to the remote object name and evaluates downloadFileName + "/${file:name}". The ${file:name} token returns the file-name header verbatim, unlike ${file:onlyname}, which applies FileUtil.stripPath to it. The resulting string was passed directly to new File(result) and blob.downloadTo(file.toPath()) with no lexical normalization and no check that the destination stayed inside the configured directory. The object name is not route-controlled data: the consumer lists the bucket, iterates every returned blob and creates one exchange per object from blob.getBlobId().getName() verbatim, and the filter option that could restrict those names is not applied at all unless it has been explicitly set. Google Cloud Storage object names are opaque UTF-8 keys that the service stores and lists exactly as written, with no server-side canonicalization, and a forward slash is only a display convention for pseudo-directories, so a key containing parent-directory segments survives round-tripping intact. An object name containing such segments therefore resolved to a location outside the configured downloadFileName directory, letting anyone able to influence the names present in the consumed bucket cause Camel to create or overwrite a file at a location of their choosing, with the privileges of the Camel process. Depending on what the process can write to, overwriting a file outside the download directory can escalate beyond the loss of integrity of that file. The downloadFileName option is an ordinary consumer parameter and carries no security marker, so nothing signalled to users that its value was not being enforced as a containment boundary. The defect is consumer-only; the producer has no download-to-file sink. Camel's other file-download consumers - camel-file, camel-ftp, camel-smb, camel-mina-sftp, camel-azure-files and the Azure Storage download paths - already constrained their local downloads to the configured directory using a path-segment boundary check; camel-google-storage was the remaining object-store download sink not covered by that work.