Opencast before 8.1 and 7.6 allows almost arbitrary identifiers for media packages and elements to be used. This can be problematic for operation and security since such identifiers are sometimes used for file system operations which may lead to an attacker being able to escape working directories and write files to other locations. In addition, Opencast's Id.toString(…) vs Id.compact(…) behavior, the latter trying to mitigate some of the file system problems, can cause errors due to identifier mismatch since an identifier may unintentionally change. This issue is fixed in Opencast 7.6 and 8.1.

Affected: Maven: org.opencastproject:base

### Impact

Opencast allows almost arbitrary identifiers for media packages and elements to be used. This can be problematic for operation and security since such identifiers are sometimes used for file system operations which may lead to an attacker being able to escape working directories and write files to other locations.

In addition, Opencast's Id.toString(…) vs Id.compact(…) behavior, the latter trying to mitigate some of the file system problems, can cause errors due to identifier mismatch since an identifier may unintentionally change.

### Patches

This issue is fixed in Opencast 7.6 and 8.1.

### Workarounds

There is no workaround for this.

### For more information

If you have any questions or comments about this advisory:

- Open an issue in [opencast/opencast](https://github.com/opencast/opencast/issues) - For security-relevant information, email us at security@opencast.org