Package Instance

Improper Authentication
In all versions of Apache Spark, the standalone resource manager accepts code to execute on a `master` host, that then runs that code on `worker` hosts. The master itself does not, by design, execute user code. A specially-crafted request to the master can, however, cause the master to execute code too. Note that this does not affect standalone clusters with authentication enabled. While the master host typically has less outbound access to other resources than a worker, the execution of code on the master is nevertheless unexpected.

Improper Authentication
Apache Spark standalone master exposes a REST API for job submission, in addition to the submission mechanism used by spark-submit. In standalone, the config property `spark.authenticate.secret` establishes a shared secret for authenticating requests to submit jobs via spark-submit. However, the REST API does not use this or any other authentication mechanism, and this is not adequately documented. In this case, a user would be able to run a driver program without authenticating, but not launch executors, using the REST API.

Cross-site Scripting
It is possible for an attacker to take advantage of a user's trust in the server to trick them into visiting a link that points to a shared Spark cluster and submits data including MHTML to the Spark master, or history server. This data, which could contain a script, would then be reflected back to the user and could be evaluated and executed by MS Windows-based clients. It is not an attack on Spark itself, but on the user, who may then execute the script inadvertently when viewing elements of the Spark web UIs.

Improper Input Validation
The Apache Spark Maven-based build includes a convenience script, `build/mvn`, that downloads and runs a zinc server to speed up compilation. It has been included in release branches since, up to and including master. This server will accept connections from external hosts by default. A specially-crafted request to the zinc server could cause it to reveal information in files readable to the developer account running the build.