{"schemaVersion":3,"id":"CVE-2020-14000","aliases":["GHSA-vc9j-fhvv-8vrf"],"status":"published","duplicateOf":null,"title":null,"description":"MIT Lifelong Kindergarten Scratch scratch-vm before 0.2.0-prerelease.20200714185213 loads extension URLs from untrusted project.json files with certain _ characters, resulting in remote code execution because the URL's content is treated as a script and is executed as a worker. The responsible code is getExtensionIdForOpcode in serialization/sb3.js. The use of _ is incompatible with a protection mechanism in older versions, in which URLs were split and consequently deserialization attacks were prevented. 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