---
title: "CVE-2016-9015\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-2016-9015?format=md
keywords: index, follow
---

# CVE-2016-9015

Publication date 11 January 2017

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**3.7 · Low**

[Score breakdown](https://ubuntu.com/security/CVE-2016-9015?format=md#impact-score)

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## Description

Versions 1.17 and 1.18 of the Python urllib3 library suffer from a
vulnerability that can cause them, in certain configurations, to not
correctly validate TLS certificates. This places users of the library with
those configurations at risk of man-in-the-middle and information leakage
attacks. This vulnerability affects users using versions 1.17 and 1.18 of
the urllib3 library, who are using the optional PyOpenSSL support for TLS
instead of the regular standard library TLS backend, and who are using
OpenSSL 1.1.0 via PyOpenSSL. This is an extremely uncommon configuration,
so the security impact of this vulnerability is low.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2016-9015?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| python-urllib3 | 16.10 yakkety | Not affected |
| 16.04 LTS xenial | Not affected |
| 14.04 LTS trusty | Not affected |
| 12.04 LTS precise | 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)

## Notes

---

### [seth-arnold](https://launchpad.net/~seth-arnold)

I'm marking our packages 'not-affected' due to upstream version
notes.

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

3.7 · Low

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 3.7 · Low |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-9015)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2016-9015)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2016-9015)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2016-9015)

### Other references

* <https://marc.info/?l=oss-security&m=147756761531433&w=2>
* <https://www.cve.org/CVERecord?id=CVE-2016-9015>