PHP object injection vulnerability in QRadar Forensics web application
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Yorick Koster, September 2019
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Abstract
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A PHP object injection vulnerability was found in the QRadar
Forensics
web application. The vulnerability can be triggered via a
specially
crafted cookie and can be used by an authenticated attacker to
execute
arbitrary commands. The commands will be executed with the
privileges of
the Apache system user.
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See also
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CVE-2020-4271 [2]
6189651 [3] - IBM QRadar SIEM is vulnerable to PHP object
injection
(CVE-2020-4271)
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Tested versions
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This issue was successfully verified on QRadar Community Edition
[4]
version 7.3.1.6 (7.3.1 Build 20180723171558).
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Fix
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IBM has released the following versions of QRader in which this
issue
has been resolved:
- QRadar / QRM / QVM / QNI 7.4.0 GA [5] (SFS)
- QRadar / QRM / QVM / QRIF / QNI 7.3.3 Patch 3 [6] (SFS)
- QRadar / QRM / QVM / QRIF / QNI 7.3.2 Patch 7 [7] (SFS)
- QRadar Incident Forensics 7.4.0 [8] (ISO)
- QRadar Incident Forensics 7.4.0 [9] (SFS)
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Introduction
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QRadar [10] is IBM's enterprise SIEM [11] solution. A free version
of
QRadar is available that is known as QRadar Community Edition [4].
This
version is limited to 50 events per second and 5,000 network flows
a
minute, supports apps, but is based on a smaller footprint for
non-enterprise use.
A PHP object injection vulnerability was found in the QRadar
Forensics
web application. The vulnerability exists in the DataSetModel class
and
can be triggered via a specially crafted cookie. By exploiting
this
issue it is possible for authenticated users to instantiate
arbitrary
PHP objects. It has been confirmed that a POP chain exists that can
be
used to execute arbitrary commands. The commands will be executed
with
the privileges of the Apache system user (generally the nobody
user).
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Details
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The Forensics web application contains functionally to save graph
data
in cookies. When a graph is viewed that was previously saved, the
data
will be restored from the cookie value(s). Saving and restoring
data is
done using PHP object serialization. The serialized data is
compressed
and encoded with base64 before it is returned as cookie to the
user.
Deserialization of graph cookies is done in the restore() method of
the
DataSetModel as is shown in the code fragment below.
/opt/ibm/forensics/html/DejaVu/Reports/DataSetModel.php:
public function restore($dataKeys, $dsize) {
if ($dsize == 0)
// No data
return null;
$cookieData = '';
foreach ($dataKeys as $dataKey) {
if (array_key_exists($dataKey, $_COOKIE)) {
$cookieData .= $_COOKIE[$dataKey];
// All done, so delete the data cookie.
setcookie($dataKey, "", time() - 3600);
} else {
error_log("MISSING COOKIE '$dataKey'");
return null;
}
}
$sz = strlen($cookieData);
if ($sz != $dsize) {
error_log("ERROR: Graph data size incorrect: expected $dsize, got
$sz");
return null;
}
try {
$dataset =
unserialize(gzuncompress(base64_decode($cookieData)));
return $dataset;
} catch (Exception $e) {
error_log("Error deserializing session data: " .
$e->getMessage());
$dataset = null;
}
return null;
}
The restore() method is called in the constructor of various
chart
classes, which all inherit from the BaseChart class. These chart
classes
are exposed in the /forensics/graphs.php page of the Forensics
web
application.
/opt/ibm/forensics/html/DejaVu/Charts.php:
abstract class BaseChart extends ParameterizedObject {
[...]
public function __construct($params=null) {
[...]
$dm = empty($dmodel) ? new DataSetModeler(null) : new
$dmodel(null);
if(array_key_exists('sid',$_GET))
$dm->setSessID($_GET['sid']);
$dataset = $dm->restore($dataKeys,$dsize);
[...]
It has been confirmed that this vulnerability can be used to
execute
arbitrary commands by sending a specially crafted cookie to the
affected
web page.
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References
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[1]
https://www.securify.nl/advisory/SFY20200406/php-object-injection-vulnerability-in-qradar-forensics-web-application.html
[2]
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-4271
[3] https://www.ibm.com/support/pages/node/6189651
[4] https://developer.ibm.com/qradar/ce/
[5]
https://www.ibm.com/support/fixcentral/swg/downloadFixes?parent=IBM%20Security&product=ibm/Other+software/IBM+Security+QRadar+SIEM&release=7.4.0&platform=Linux&function=fixId&fixids=7.4.0-QRADAR-QRSIEM-20200304205308&includeRequisites=1&includeSupersedes=0&downloadMethod=http
[6]
https://www.ibm.com/support/fixcentral/swg/downloadFixes?parent=IBM%20Security&product=ibm/Other+software/IBM+Security+QRadar+SIEM&release=7.3.0&platform=Linux&function=fixId&fixids=7.3.3-QRADAR-QRSIEM-20200409085709&includeRequisites=1&includeSupersedes=0&downloadMethod=http
[7]
https://www.ibm.com/support/fixcentral/swg/downloadFixes?parent=IBM%20Security&product=ibm/Other+software/IBM+Security+QRadar+SIEM&release=7.3.0&platform=Linux&function=fixId&fixids=7.3.2-QRADAR-QRSIEM-20200406171249&includeRequisites=1&includeSupersedes=0&downloadMethod=http
[8]
https://www.ibm.com/support/fixcentral/swg/downloadFixes?parent=IBM%20Security&product=ibm/Other+software/IBM+Security+QRadar+Incident+Forensics&release=7.4.0&platform=Linux&function=fixId&fixids=7.4.0-QRADAR-QIFFULL-2019.18.0.20200304205308&includeRequisites=1&includeSupersedes=0&downloadMethod=http
[9]
https://www.ibm.com/support/fixcentral/swg/downloadFixes?parent=IBM%20Security&product=ibm/Other+software/IBM+Security+QRadar+Incident+Forensics&release=7.4.0&platform=Linux&function=fixId&fixids=7.4.0-QRADAR-QIFSFS-2019.18.0.20200304205308&includeRequisites=1&includeSupersedes=0&downloadMethod=http
[10] https://www.ibm.com/security/security-intelligence/qradar
[11]
https://en.wikipedia.org/wiki/Security_information_and_event_management
