cve/2019/CVE-2019-9901.md

### [CVE-2019-9901](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-9901)
![](https://img.shields.io/static/v1?label=Product&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brighgreen)

### Description

Envoy 1.9.0 and before does not normalize HTTP URL paths. A remote attacker may craft a relative path, e.g., something/../admin, to bypass access control, e.g., a block on /admin. A backend server could then interpret the non-normalized path and provide an attacker access beyond the scope provided for by the access control policy.

### POC

#### Reference
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-xcx5-93pw-jw2w

#### Github
- https://github.com/alphaSeclab/sec-daily-2019
- https://github.com/solo-io/envoy-cves