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 a...

Description

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.

Metrics

CVSS 3.1

5.4/10

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

EPSS Probability

0.38%

30.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-862

Affected Software

Vendor	Product	Versions
Openedx	Xblock-Lti-Consumer	>= 7.0.0, < 7.2.2

References

https://github.com/openedx/xblock-lti-consumer/security/advisories/GHSA-7j9p-67mm-5g87Third Party Advisory
https://github.com/openedx/xblock-lti-consumer/security/advisories/GHSA-7j9p-67mm-5g87Third Party Advisory

Timeline

Published: Jan 26, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is 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.

How severe is CVE-2023-23611?

CVE-2023-23611 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.38% probability of exploitation in the next 30 days.

How do I fix CVE-2023-23611?

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.