Vuln Title: The CollabNet Subversion Edge Management frontend user credential

(hash) leak

Date: 28.06.2015

Author: otr

Software Link: https://www.open.collab.net/downloads/svnedge

Vendor: CollabNet

Version: 4.0.11

Tested on: Fedora Linux

Type: Credential leak

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 leaks the unsalted MD5 hash of
password of the currently logged in user via a "POST /csvn/user/index" request.
An attacker that exploits an XSS or has gained a valid session via other means
is able to retrieve the unsalted MD5 hash of the corresponding user and easily
crack the hash in order to know the users password.

Request 1 (set password)
POST /csvn/user/index HTTP/1.1
Host: example.com:4434
[…]
id=5&version=15&passwd_change_active=false&passwd=aaaaa&confirmPasswd=&realUserName=XXX&email=YYYY&description=ZZZ&_action_update=Update

Response 1:
HTTP/1.1 302 Found
[…]
Location: https://example.com:4434/csvn/user/show/5
Content-Length: 0

Request 2 (generated by clicking edit in the following page; request below the iamge):
GET /csvn/user/edit/5 HTTP/1.1
Host: example.com:4434
[…]
Cookie: SESSID=xxxxxxxxxxxxxxxxxxxx;

Response 2 (leaked hash read from DB and echoed back into password change form):
HTTP/1.1 200 OK
[…]
<input type="password" id="passwd" name="passwd" value="4db81436059d080afe532cc0cbd1cea5"/>

Fix proposal:

Do not echo the current hash in the database back to the user when changing the
password. Only accept passwords as input fields and no hashes.

Vendor fix:

The leak is plugged.