CVE-2021-36539

moderate-risk

Published 2023-01-26

Instructure Canvas LMS didn't properly deny access to locked/unpublished files when the unprivileged user access the DocViewer based file preview URL (canvadoc_session_url).

Do I need to act?

0.27% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 6.5/10 Medium

NETWORK / LOW complexity

Affected Products (1)

Canvas Learning Management Service

Affected Vendors

Instructure

References (4)

Exploit https://github.com/gaukas/instructure-canvas-file-oracle

Exploit https://github.com/instructure/canvas-lms/issues/1905

Exploit https://github.com/gaukas/instructure-canvas-file-oracle

Exploit https://github.com/instructure/canvas-lms/issues/1905

/ 100

moderate-risk

Severity 24/34 · High

Exploitability 1/34 · Minimal

Exposure 5/34 · Minimal