CVE-2021-21234: Directory Traversal in spring-boot-actuator-logview

Impact

The nature of this library is to expose a log file directory via admin (spring boot actuator) HTTP endpoints. Both the filename to view and a base folder (relative to the logging folder root) can be specified via request parameters. While the filename parameter was checked to prevent directory traversal exploits (so that filename=../somefile would not work), the base folder parameter was not sufficiently checked, so that filename=somefile&base=../ could access a file outside the logging base directory).

Patches

The vulnerability has been patched in release 0.2.13. Any users of 0.2.12 should be able to update without any issues as there are no other changes in that release.

Workarounds

There is no workaround to fix the vulnerability other than updating or removing the dependency. However, removing read access of the user the application is run with to any directory not required for running the application can limit the impact. Additionally, access to the logview endpoint can be limited by deploying the application behind a reverse proxy.

For more information

If you have any questions or comments about this advisory:

• Open an issue in the github repo