---
title: "CVE-2016-4975\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-2016-4975?format=md
keywords: index, follow
---

# CVE-2016-4975

Publication date 14 August 2018

Last updated 25 August 2025

---

Ubuntu priority

**Low**

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

## Cvss 3 Severity Score

**6.1 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2016-4975?format=md#impact-score)

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## Description

Possible CRLF injection allowing HTTP response splitting attacks for sites
which use mod\_userdir. This issue was mitigated by changes made in 2.4.25
and 2.2.32 which prohibit CR or LF injection into the "Location" or other
outbound header key or value. Fixed in Apache HTTP Server 2.4.25 (Affected
2.4.1-2.4.23). Fixed in Apache HTTP Server 2.2.32 (Affected 2.2.0-2.2.31).

[Read the notes from the security team](https://ubuntu.com/security/CVE-2016-4975?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| apache2 | 19.04 disco | Not affected |
| 18.10 cosmic | Not affected |
| 18.04 LTS bionic | Not affected |
| 16.04 LTS xenial | Fixed 2.4.18-2ubuntu3.2 |
| 14.04 LTS trusty | Fixed 2.4.7-1ubuntu4.15 |

---

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

## Notes

---

### [mdeslaur](https://launchpad.net/~mdeslaur)

fixed by CVE-2016-8743 commits

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

6.1 · Medium

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 6.1 · Medium |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-4975)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2016-4975)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2016-4975)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2016-4975)

### Other references

* <https://httpd.apache.org/security/vulnerabilities_22.html#CVE-2016-4975>
* <https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2016-4975>
* <https://www.cve.org/CVERecord?id=CVE-2016-4975>