SEC Consult SA-20131004-0 :: SQL injection vulnerability in Zabbix Oct 04 2013 08:26AM
SEC Consult Vulnerability Lab (research sec-consult com)
SEC Consult Vulnerability Lab Security Advisory < 20131004-0 >
title: SQL injection vulnerability
product: Zabbix
vulnerable version: <=2.0.8
fixed version: 2.0.9rc1
CVE number: CVE-2013-5743
impact: critical
homepage: http://www.zabbix.com/
found: 2013-09-03
by: Bernhard Schildendorfer
SEC Consult Vulnerability Lab

Vendor description:
"Zabbix is the ultimate open source availability and performance monitoring
solution. Zabbix offers advanced monitoring, alerting, and visualization
features today which are missing in other monitoring systems, even some of the
best commercial ones."

Source: http://www.zabbix.com/product.php

Business recommendation:
By exploiting this SQL injection vulnerability, an authenticated attacker (or
guest user) is able to gain full access to the database. This causes a
privilege escalation to power users as well as a possible compromise of the
database and operating system the database is running on.

Because of the functionalities Zabbix offers, an attacker with admin
privileges could be able (depending on the actual configuration) to execute
arbitrary OS commands on the configured Zabbix hosts. This results in a severe
impact to the monitored infrastructure.

Although the attacker needs to be authenticated in general, the system could
also be at risk if the adversary has no user account. Zabbix offers a guest
mode which provides a low privileged default account for users without
password. If this guest mode is enabled, the SQL injection vulnerability can
be exploited unauthenticated.

Vulnerability overview/description:
The PHP JSON API provides access to different classes which lack input
validation of some of their parameters. This can be exploited to inject into
SQL query statements. By exploiting this vulnerability, an attacker gains
access to all records stored in the database with the privileges of the Zabbix
database user.

Proof of concept:
The affected PHP file api_jsonrpc.php handles JSON requests to the Zabbix API
which get, after passing to class.cjsonrpc.php, dispatched by
class.czbxrpc.php to the actual (vulnerable) API classes located in

The example proof of concept exploit has been removed from this advisory.

A quick search in the source code revealed, that at least the following
methods are also vulnerable with the given parameters. Not all of them were

- alert.get // parameter: time_from, time_till
- event.get // parameter: object, source, eventid_from, eventid_till
- graphitem.get // parameter: type
- graph.get // parameter: type
- graphprototype.get // parameter: type
- history.get // parameter: time_from, time_till
- trigger.get // parameter: lastChangeSince, lastChangeTill, min_severity
- triggerprototype.get // parameter: min_severity
- usergroup.get // parameter: status

Because no prepared statements are used to query the database, further
injection points may be in place where prior validation fails.

Vulnerable / tested versions:

Zabbix 2.0.8

Vendor contact timeline:
2013-09-10: Contacting vendor through sales (at) zabbix (dot) com [email concealed]
2013-09-10: Initial vendor response
2013-09-10: Forwarding security advisory to vendor
2013-09-10: Vendor acknowledges that the advisory was received
2013-09-11: Vendor confirmed the issue
2013-10-02: Patch released by vendor
2013-10-04: SEC Consult releases coordinated security advisory.

According to the vendor, patches for the following Zabbix versions are
available for download. They were not tested by SEC Consult.
1.8.18rc1: https://support.zabbix.com/secure/attachment/24448/ZBX-7091-1.8.18rc1.pa
1.8.2: https://support.zabbix.com/secure/attachment/24447/ZBX-7091-1.8.2.patch
2.0.8: https://support.zabbix.com/secure/attachment/24449/ZBX-7091-2.0.8.patch
2.0.9rc1: https://support.zabbix.com/secure/attachment/24450/ZBX-7091-2.0.9rc1.pat
2.1.7: https://support.zabbix.com/secure/attachment/24451/ZBX-7091-2.1.7.patch

Additional information is available on the vendor's bug tracking page:

No workaround available.

Advisory URL:

SEC Consult Vulnerability Lab

SEC Consult
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EOF Bernhard Schildendorfer / @2013

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