minor #5172 [Contributing][Code] add missing security advisories (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
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[Contributing][Code] add missing security advisories

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets |

Commits
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e34d663 add missing security advisories

Author: wouterj

contributing/code/security.rst

@@ -96,6 +96,12 @@ Security Advisories
 This section indexes security vulnerabilities that were fixed in Symfony
 releases, starting from Symfony 1.0.0:
 
+* April 1, 2015: `CVE-2015-2309: Unsafe methods in the Request class <http://symfony.com/blog/cve-2015-2309-unsafe-methods-in-the-request-class>`_ (Symfony 2.3.27, 2.5.11 and 2.6.6)
+* April 1, 2015: `CVE-2015-2308: Esi Code Injection <http://symfony.com/blog/cve-2015-2308-esi-code-injection>`_ (Symfony 2.3.27, 2.5.11 and 2.6.6)
+* September 3, 2014: `CVE-2014-6072: CSRF vulnerability in the Web Profiler <http://symfony.com/blog/cve-2014-6072-csrf-vulnerability-in-the-web-profiler>`_ (Symfony 2.3.19, 2.4.9 and 2.5.4)
+* September 3, 2014: `CVE-2014-6061: Security issue when parsing the Authorization header <http://symfony.com/blog/cve-2014-6061-security-issue-when-parsing-the-authorization-header>`_ (Symfony 2.3.19, 2.4.9 and 2.5.4)
+* September 3, 2014: `CVE-2014-5245: Direct access of ESI URLs behind a trusted proxy <http://symfony.com/blog/cve-2014-5245-direct-access-of-esi-urls-behind-a-trusted-proxy>`_ (Symfony 2.3.19, 2.4.9 and 2.5.4)
+* September 3, 2014: `CVE-2014-5244: Denial of service with a malicious HTTP Host header <http://symfony.com/blog/cve-2014-5244-denial-of-service-with-a-malicious-http-host-header>`_ (Symfony 2.3.19, 2.4.9 and 2.5.4)
 * July 15, 2014: `Security releases: Symfony 2.3.18, 2.4.8, and 2.5.2 released <http://symfony.com/blog/security-releases-cve-2014-4931-symfony-2-3-18-2-4-8-and-2-5-2-released>`_ (`CVE-2014-4931 <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-4931>`_)
 * October 10, 2013: `Security releases: Symfony 2.0.25, 2.1.13, 2.2.9, and 2.3.6 released <http://symfony.com/blog/security-releases-cve-2013-5958-symfony-2-0-25-2-1-13-2-2-9-and-2-3-6-released>`_ (`CVE-2013-5958 <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-5958>`_)
 * August 7, 2013: `Security releases: Symfony 2.0.24, 2.1.12, 2.2.5, and 2.3.3 released <http://symfony.com/blog/security-releases-symfony-2-0-24-2-1-12-2-2-5-and-2-3-3-released>`_ (`CVE-2013-4751 <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-4751>`_ and `CVE-2013-4752 <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-4752>`_)