Auth bypass in Openedx Xblock-Lti-Consumer

CVE-2023-23611

LTI Consumer XBlock implements the consumer side of the LTI specification enabling integration of third-party LTI provider tools. Versions 7.0.0 and above, prior to 7.2.2, are vulnerable to Missing Authorization. Any LTI tool that is integrated with on the Open edX platform can post a grade back for any LTI XBlock so long as it knows or can guess the block location for that XBlock. An LTI tool submits scores to the edX platform for line items. The code that uploads that score to the LMS grade tables determines which XBlock to upload the grades for by reading the resource_link_id field of the associated line item. The LTI tool may submit any value for the resource_link_id field, allowing a malicious LTI tool to submit scores for any LTI XBlock on the platform. The impact is a loss of integrity for LTI XBlock grades. This issue is patched in 7.2.2. No workarounds exist.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (29.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 29.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2023-23611: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-23611?
CVE-2023-23611 is a medium-severity vulnerability in Openedx Xblock-Lti-Consumer, classified under Missing Authorization. CVSS score: 5.4/10. Published 2023-01-26.
How severe is CVE-2023-23611?
Medium severity. CVSS v3 base score is 5.4 out of 10.