CVE-2021-21318

MEDIUMCVSS 5.4/10EPSS 0.71%

Last modified

CVE-2021-21318 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. Opencast is a free, open-source platform to support the management of educational audio and video content. In Opencast before version 9.2 there is a vulnerability in which publishing an episode with strict access rules will overwrite the currently set series access. EPSS estimates a 0.71% chance of exploitation in the next 30 days.

Description

Opencast is a free, open-source platform to support the management of educational audio and video content. In Opencast before version 9.2 there is a vulnerability in which publishing an episode with strict access rules will overwrite the currently set series access. This allows for an easy denial of access for all users without superuser privileges, effectively hiding the series. Access to series and series metadata on the search service (shown in media module and player) depends on the events published which are part of the series. Publishing an event will automatically publish a series and update access to it. Removing an event or republishing the event should do the same. Affected versions of Opencast may not update the series access or remove a published series if an event is being removed. On removal of an episode, this may lead to an access control list for series metadata with broader access rules than the merged access rules of all remaining events, or the series metadata still being available although all episodes of that series have been removed. This problem is fixed in Opencast 9.2.

Metrics

CVSS 3.1
5.4/10

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

EPSS Probability
0.71%

48.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
ApereoOpencast< 9.2

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-21318?
Opencast is a free, open-source platform to support the management of educational audio and video content. In Opencast before version 9.2 there is a vulnerability in which publishing an episode with strict access rules will overwrite the currently set series access. This allows for an easy denial of access for all users without superuser privileges, effectively hiding the series. Access to series and series metadata on the search service (shown in media module and player) depends on the events published which are part of the series. Publishing an event will automatically publish a series and update access to it. Removing an event or republishing the event should do the same. Affected versions of Opencast may not update the series access or remove a published series if an event is being removed. On removal of an episode, this may lead to an access control list for series metadata with broader access rules than the merged access rules of all remaining events, or the series metadata still being available although all episodes of that series have been removed. This problem is fixed in Opencast 9.2.
How severe is CVE-2021-21318?
CVE-2021-21318 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.71% probability of exploitation in the next 30 days.
How do I fix CVE-2021-21318?
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-2021-21318?

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

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Source: NVD / NIST