Grafana Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') Vulnerability (CVE-2021-43813)

Description

Grafana is an open-source platform for monitoring and observability. Grafana prior to versions 8.3.2 and 7.5.12 contains a directory traversal vulnerability for fully lowercase or fully uppercase .md files. The vulnerability is limited in scope, and only allows access to files with the extension .md to authenticated users only. Grafana Cloud instances have not been affected by the vulnerability. Users should upgrade to patched versions 8.3.2 or 7.5.12. For users who cannot upgrade, running a reverse proxy in front of Grafana that normalizes the PATH of the request will mitigate the vulnerability. The proxy will have to also be able to handle url encoded paths. Alternatively, for fully lowercase or fully uppercase .md files, users can block /api/plugins/.*/markdown/.* without losing any functionality beyond inlined plugin help text.