Graylog server has partial path traversal vulnerability in Support Bundle feature

A partial path traversal vulnerability exists in Graylog's Support Bundle feature. The vulnerability is caused by incorrect user input validation in an HTTP API resource.

Thanks to weiweiwei9811 for reporting this vulnerability and providing detailed information.

Impact

Graylog's Support Bundle feature allows an attacker with valid Admin role credentials to download or delete files in sibling directories of the support bundle directory.

The default data_dir in operating system packages (DEB, RPM) is set to /var/lib/graylog-server. The data directory for the Support Bundle feature is always <data_dir>/support-bundle.

Due to the partial path traversal vulnerability, an attacker with valid Admin role credentials can read or delete files in directories that start with a /var/lib/graylog-server/support-bundle directory name.

The vulnerability would allow the download or deletion of files in the following example directories.

• /var/lib/graylog-server/support-bundle-test
• /var/lib/graylog-server/support-bundlesdirectory

For the Graylog and Graylog Enterprise Docker images, the data_dir is set to /usr/share/graylog/data by default.

Patches

The vulnerability is fixed in Graylog version 5.1.3 and later.

Workarounds

Block all HTTP requests to the following HTTP API endpoints by using a reverse proxy server in front of Graylog.

• GET /api/system/debug/support/bundle/download/{filename}
• DELETE /api/system/debug/support/bundle/{filename}