Vulnerability Details : CVE-2021-43821
Potential exploit
Opencast is an Open Source Lecture Capture & Video Management for Education. Opencast before version 9.10 or 10.6 allows references to local file URLs in ingested media packages, allowing attackers to include local files from Opencast's host machines and making them available via the web interface. Before Opencast 9.10 and 10.6, Opencast would open and include local files during ingests. Attackers could exploit this to include most local files the process has read access to, extracting secrets from the host machine. An attacker would need to have the privileges required to add new media to exploit this. But these are often widely given. The issue has been fixed in Opencast 10.6 and 11.0. You can mitigate this issue by narrowing down the read access Opencast has to files on the file system using UNIX permissions or mandatory access control systems like SELinux. This cannot prevent access to files Opencast needs to read though and we highly recommend updating.
Products affected by CVE-2021-43821
- cpe:2.3:a:apereo:opencast:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-43821
0.98%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 75 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-43821
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
4.0
|
MEDIUM | AV:N/AC:L/Au:S/C:P/I:N/A:N |
8.0
|
2.9
|
NIST | |
7.7
|
HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
3.1
|
4.0
|
NIST | |
9.9
|
CRITICAL | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
3.1
|
6.0
|
GitHub, Inc. |
CWE ids for CVE-2021-43821
-
The product makes files or directories accessible to unauthorized actors, even though they should not be.Assigned by:
- nvd@nist.gov (Primary)
- security-advisories@github.com (Secondary)
References for CVE-2021-43821
-
https://github.com/opencast/opencast/commit/65c46b9d3e8f045c544881059923134571897764
Merge pull request from GHSA-59g4-hpg3-3gcp · opencast/opencast@65c46b9 · GitHubPatch;Third Party Advisory
-
https://github.com/opencast/opencast/security/advisories/GHSA-59g4-hpg3-3gcp
Files Accessible to External Parties · Advisory · opencast/opencast · GitHubExploit;Third Party Advisory
-
https://mvnrepository.com/artifact/org.opencastproject/opencast-ingest-service-impl
Please Wait... | CloudflareThird Party Advisory
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https://github.com/opencast/opencast/blob/69952463971cf578363e3b97d8edaf334ff51253/modules/ingest-service-impl/src/main/java/org/opencastproject/ingest/impl/IngestServiceImpl.java#L1587
opencast/IngestServiceImpl.java at 69952463971cf578363e3b97d8edaf334ff51253 · opencast/opencast · GitHubPatch;Third Party Advisory
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