CVEs-PoC/2017/CVE-2017-0904.md

### [CVE-2017-0904](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-0904)
![](https://img.shields.io/static/v1?label=Product&message=private_address_check%20ruby%20gem&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=Use%20of%20Inherently%20Dangerous%20Function%20(CWE-242)&color=brighgreen)

### Description

The private_address_check ruby gem before 0.4.0 is vulnerable to a bypass due to use of Ruby's Resolv.getaddresses method, which is OS-dependent and should not be relied upon for security measures, such as when used to blacklist private network addresses to prevent server-side request forgery.

### POC

#### Reference
- https://edoverflow.com/2017/ruby-resolv-bug/
- https://github.com/jtdowney/private_address_check/issues/1
- https://hackerone.com/reports/287245

#### Github
No PoCs found on GitHub currently.