CVE-2020-14000
9.8
CRITICAL · CVSS 3.1 · EPSS 2.8% (pctl 86)
In your normal cycle
Critical by CVSS (9.8), but no sign of active exploitation.
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. NOTE: the scratch.mit.edu hosted service is not affected because of the lack of worker scripts.
Scoring
| CVSS | 9.8 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 2.83% — more likely to be exploited than 86% of all CVEs |
| Weakness | CWE-502 |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2020-07-16 |
| Last modified | 2026-06-17 |
Affected (1)
| Vendor | Product |
|---|---|
| mit | scratch-vm |
References
→ the Explorer · watch your stack · NVD