Malcolm's nginx Lua role-based access control (RBAC) layer decides whether an authenticated user may reach a role-restricted path (e.g. /htadmin, /auth, /adminlogin, /arkime/api/esadmin, NetBox, upload endpoints) by pattern-matching the raw, percent-encoded request URI. Nginx itself, however, selects which location block actually serves the request using the percent-decoded, normalized URI. Because the RBAC check never percent-decodes its input, an authenticated low-privilege user can request an admin-only path using percent-encoding (e.g. /%68tadmin.php) and have nginx route it to the restricted location while the Lua RBAC gate evaluating the un-decoded raw string finds no matching restriction and grants access.

The Arkime live capture service (arkime-live) in Malcolm runs with networkmode: host, exposing port 8005 on all network interfaces (viewHost=0.0.0.0). Arkime trusts the X-Forwarded-User header from any IP address (userAuthIps=::,0.0.0.0/0) and auto-creates users with full access. The passwordSecret is hardcoded to the public value "Malcolm". A network-adjacent attacker bypasses nginx entirely by connecting directly to port 8005 with a forged identity header.

Malcolm file-upload component ships the upstream FilePond PHP server (pqina/filepond-server-php) largely unmodified: Dockerfile copies all upstream .php files and Malcolm only overwrites config.php and submit.php. Upstream index.php exposes a fetch API route that instructs the server to download an arbitrary URL with curl (including FOLLOWLOCATION) and, for HEAD requests, stores the fetched response body in the upload container's transfer directory and returns the transfer ID to the caller, enabling full readback of the fetched content.

Malcolm's nginx based reverse proxy contains a URL path normalization inconsistency between its Lua based role-based access control (RBAC) authorization layer and nginx's own request routing logic. An authenticated user can craft a specially formatted request path to bypass role-based restrictions and reach administrative or role gated endpoints they should not have access to. This affects all restricted paths protected by the RBAC authorization layer, including file upload, PHP server, htadmin, and authentication management interfaces.

Malcolm is a network traffic analysis tool suite. Prior to version 26.07.0, safe-extract.py extracts uploaded archives with no limit on entry count, directory depth, total entries, or output size. A small malicious archive containing a large number of directory or file entries causes the filebeat processing container to create an unbounded number of filesystem objects, exhausting inodes or filesystem metadata and denying service to the processing pipeline and any service sharing the same mount. Version 26.07.0 fixes the issue.