---
title: "CVE-2016-8860\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-2016-8860?format=md
keywords: index, follow
---

# CVE-2016-8860

Publication date 4 January 2017

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**7.5 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2016-8860?format=md#impact-score)

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## Description

Tor before 0.2.8.9 and 0.2.9.x before 0.2.9.4-alpha had internal functions
that were entitled to expect that buf\_t data had NUL termination, but the
implementation of or/buffers.c did not ensure that NUL termination was
present, which allows remote attackers to cause a denial of service
(client, hidden service, relay, or authority crash) via crafted data.

### From the Ubuntu Security Team

It was discovered that Tor improperly NUL terminated data. An attacker
could possibly use this to cause a crash and denial of service.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| tor | 18.10 cosmic | Not affected |
| 18.04 LTS bionic | Not affected |
| 17.10 artful | Not affected |
| 17.04 zesty | Not affected |
| 16.10 yakkety | Ignored end of life |
| 16.04 LTS xenial | Not affected |
| 14.04 LTS trusty | Fixed 0.2.4.27-1ubuntu0.1 |
| 12.04 LTS precise | Ignored end of life |

---

* [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**

7.5 · High

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.5 · High |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-8860)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2016-8860)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2016-8860)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2016-8860)

### Other references

* <https://trac.torproject.org/projects/tor/ticket/20384>
* <https://blog.torproject.org/blog/tor-0289-released-important-fixes>
* <https://github.com/torproject/tor/commit/3cea86eb2fbb65949673eb4ba8ebb695c87a57ce>
* <http://www.openwall.com/lists/oss-security/2016/10/18/11>
* <https://www.cve.org/CVERecord?id=CVE-2016-8860>
