OpenPLC Runtime vulnerabilities

OpenPLC Runtime v3's compile_program function parses directives from uploaded Structured Text (.st) files and writes referenced content without validating that the file path stays within the ./core directory. A path-validation function exists but is never invoked from compile_program.

OpenPLC Runtime v3 has an authenticated arbitrary file write vulnerability in the legacy web UI program upload workflow. An attacker can supply an arbitrary filename stored in the database and used as the destination path without validation, allowing file writes anywhere writable by the webserver process.

OpenPLC Runtime v3 contains an input validation flaw in the /upload-program-action endpoint: the epoch_time field supplied during program uploads is not validated and can be crafted to induce corruption of the programs database. After a successful malformed upload the runtime continues to operate until a restart; on restart the runtime can fail to start because of corrupted database entries, resulting in persistent denial of service requiring complete rebase of the product to recover. This vulnerability was remediated by commit 095ee09.