---
title: "CVE-2018-14773\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2018-14773?format=md
keywords: index, follow
---

# CVE-2018-14773

Publication date 3 August 2018

Last updated 26 August 2025

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**6.5 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2018-14773?format=md#impact-score)

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## Description

An issue was discovered in Http Foundation in Symfony 2.7.0 through 2.7.48,
2.8.0 through 2.8.43, 3.3.0 through 3.3.17, 3.4.0 through 3.4.13, 4.0.0
through 4.0.13, and 4.1.0 through 4.1.2. It arises from support for a
(legacy) IIS header that lets users override the path in the request URL
via the X-Original-URL or X-Rewrite-URL HTTP request header. These headers
are designed for IIS support, but it's not verified that the server is in
fact running IIS, which means anybody who can send these requests to an
application can trigger this. This affects
\Symfony\Component\HttpFoundation\Request::prepareRequestUri() where
X-Original-URL and X\_REWRITE\_URL are both used. The fix drops support for
these methods so that they cannot be used as attack vectors such as web
cache poisoning.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| symfony | 26.04 LTS resolute | Not affected |
| 25.10 questing | Not affected |
| 25.04 plucky | Not affected |
| 24.10 oracular | Not affected |
| 24.04 LTS noble | Not affected |
| 23.10 mantic | Not affected |
| 23.04 lunar | Not affected |
| 22.10 kinetic | Not affected |
| 22.04 LTS jammy | Not affected |
| 21.10 impish | Not affected |
| 21.04 hirsute | Not affected |
| 20.10 groovy | Not affected |
| 20.04 LTS focal | Not affected |
| 19.10 eoan | Not affected |
| 19.04 disco | Not affected |
| 18.10 cosmic | Not affected |
| 18.04 LTS bionic | Vulnerable |
| 16.04 LTS xenial | Vulnerable |
| 14.04 LTS trusty | Not in release |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

6.5 · Medium

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | Low |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | None |
  | Integrity impact | High |
  | Availability impact | None |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 6.5 · Medium |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-14773)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2018-14773)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2018-14773)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2018-14773)

### Other references

* <https://symfony.com/blog/cve-2018-14773-remove-support-for-legacy-and-risky-http-headers>
* <https://www.cve.org/CVERecord?id=CVE-2018-14773>