If an application allows enter an URL in a form field and built-in URLValidator is used, it is possible to prepare a special URL which will be used to overload server process when performing validation of the URL. Solution is to upgrade to Apache Struts version 2.5.12.
http://struts.apache.org/docs/s2-047.html
http://www.oracle.com/technetwork/security-advisory/alert-cve-2017-9805-3889403.html
http://www.securityfocus.com/bid/99563
http://www.securitytracker.com/id/1039114
https://lists.apache.org/thread.html/[email protected]%3Cannouncements.struts.apache.org%3E
Source: MITRE
Published: 2017-07-13
Updated: 2018-07-08
Type: CWE-20
Base Score: 4.3
Vector: AV:N/AC:M/Au:N/C:N/I:N/A:P
Impact Score: 2.9
Exploitability Score: 8.6
Severity: MEDIUM
Base Score: 5.9
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Impact Score: 3.6
Exploitability Score: 2.2
Severity: MEDIUM