What is CVE-2021-40531?

CVE-2021-40531 is a critical-severity vulnerability in Apple macOS, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2021-09-06.

How severe is CVE-2021-40531?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2021-40531 known to be exploited?

4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Arbitrary file upload in Apple macOS

CVE-2021-40531

Sketch before 75 allows library feeds to be used to bypass file quarantine. Files are automatically downloaded and opened, without the com.apple.quarantine extended attribute. This results in remote code execution, as demonstrated by CommandString in a terminal profile to Terminal.app.

Vulnerability class: Unrestricted File Upload

EPSS: 0.328 (98.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Apple Macos
Sketch
N/a — versions n/a

Weakness classification (CWE)

CWE-434 — Unrestricted Upload of File with Dangerous Type

Public proof-of-concept exploits

References

cve@mitre.org (Patch, x_refsource_MISC, Release Notes, Vendor Advisory)
cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)

Frequently asked questions

What is CVE-2021-40531?: CVE-2021-40531 is a critical-severity vulnerability in Apple macOS, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2021-09-06.
How severe is CVE-2021-40531?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-40531 known to be exploited?: 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.