Opencast Elasticsearch Integration Infinite Loop Vulnerability
CVE-2024-52797 Published on November 21, 2024
Searching Opencast may cause a denial of service
Opencast is free and open source software for automated video capture and distribution. First noticed in Opencast 13 and 14, Opencast's Elasticsearch integration may generate syntactically invalid Elasticsearch queries in relation to previously acceptable search queries. From Opencast version 11.4 and newer, Elasticsearch queries are retried a configurable number of times in the case of error to handle temporary losses of connection to Elasticsearch. These invalid queries would fail, causing the retry mechanism to begin requerying with the same syntactically invalid query immediately, in an infinite loop. This causes a massive increase in log size which can in some cases cause a denial of service due to disk exhaustion.
Opencast 13.10 and Opencast 14.3 contain patches which address the base issue, with Opencast 16.7 containing changes which harmonize the search behaviour between the admin UI and external API. Users are strongly recommended to upgrade as soon as possible if running versions prior to 13.10 or 14.3. While the relevant endpoints require (by default) `ROLE_ADMIN` or `ROLE_API_SERIES_VIEW`, the problem queries are otherwise innocuous. This issue could be easily triggered by normal administrative work on an affected Opencast system. Those who run a version newer than 13.10 and 14.3 and see different results when searching in their admin UI vs your external API or LMS, may resolve the issue by upgrading to 16.7. No known workarounds for the vulnerability are available.
Vulnerability Analysis
CVE-2024-52797 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
Allocation of Resources Without Limits or Throttling
The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.
Affected Versions
opencast:- Version >= 11.4, < 13.10 is affected.
- Version >= 14.0, < 14.3 is affected.
- Version >= 15.0, < 16.7 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.