### [CVE-2017-9804](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-9804)
![](https://img.shields.io/static/v1?label=Product&message=Apache%20Struts&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=A%20regular%20expression%20Denial%20of%20Service%20when%20using%20URLValidator%20(similar%20to%20S2-044%20%26%20S2-047)&color=brighgreen)

### Description

In Apache Struts 2.3.7 through 2.3.33 and 2.5 through 2.5.12, if an application allows entering a 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.  NOTE: this vulnerability exists because of an incomplete fix for S2-047 / CVE-2017-7672.

### POC

#### Reference
No PoCs from references.

#### Github
- https://github.com/ARPSyndicate/cvemon
- https://github.com/IkerSaint/VULNAPP-vulnerable-app
- https://github.com/PEAKWEI/WsylibBookRS
- https://github.com/khodges42/Etrata
- https://github.com/pctF/vulnerable-app
- https://github.com/wemindful/WsylibBookRS