Denial of Service (DoS) Affecting org.apache.struts.xwork:xwork-core package, versions [2.0.0,



    Attack Complexity Low

    Threat Intelligence

    EPSS 1.64% (88th percentile)
Expand this section
5.3 medium

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • published 24 Jan 2014
  • disclosed 20 Dec 2011
  • credit Johno Crawford

How to fix?

Upgrade org.apache.struts.xwork:xwork-core to version or higher.


org.apache.struts.xwork:xwork-core is a generic command pattern framework. It forms the core of Struts 2.

Affected versions of this package are vulnerable to Denial of Service (DoS). It allows remote attackers to cause a denial of service (CPU consumption) via a long parameter name, which is processed as an OGNL expression.


Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

  • High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

  • Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package