# CVE-2018-16471: ruby-rack: There is a possible XSS vulnerability in Rack before 2.0.6 and 1.6.11

CVE-2018-16471 is fixed in ruby-rack on 1 platform by ruby-rack 1.6.4-4ubuntu0.1 (version 1.6.4-4ubuntu0.1), released November 12, 2018. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2018-16471
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0189
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Nov 12, 2018

## Description

There is a possible XSS vulnerability in Rack before 2.0.6 and 1.6.11. Carefully crafted requests can impact the data returned by the `scheme` method on `Rack::Request`. Applications that expect the scheme to be limited to 'http' or 'https' and do not escape the return value could be vulnerable to an XSS attack. Note that applications using the normal escaping mechanisms provided by Rails may not impacted, but applications that bypass the escaping mechanisms, or do not use them may be vulnerable.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | ruby-rack Ubuntu 18.04.6 LTS (bionic) | 1.6.4-4ubuntu0.1 | [ruby-rack 1.6.4-4ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-ruby-rack-1.6.4-4ubuntu0.1.md) | Nov 12, 2018 |

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