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CVE-2020-14000

CRITICALCVSS 9.8/10EPSS 2.83%

Last modified

CVE-2020-14000 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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. EPSS estimates a 2.83% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
2.83%

84.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
MitScratch-Vm< 0.2.0-prerelease.20200714185213

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2020-14000?
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.
How severe is CVE-2020-14000?
CVE-2020-14000 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 2.83% probability of exploitation in the next 30 days.
How do I fix CVE-2020-14000?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-14000?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST