---
title: "CVE-2016-2167\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-2016-2167?format=md
keywords: index, follow
---

# CVE-2016-2167

Publication date 5 May 2016

Last updated 25 August 2025

---

Ubuntu priority

**Low**

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

## Cvss 3 Severity Score

**6.8 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2016-2167?format=md#impact-score)

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## Description

The canonicalize\_username function in svnserve/cyrus\_auth.c in Apache
Subversion before 1.8.16 and 1.9.x before 1.9.4, when Cyrus SASL
authentication is used, allows remote attackers to authenticate and bypass
intended access restrictions via a realm string that is a prefix of an
expected repository realm string.

### From the Ubuntu Security Team

Daniel Shahaf and James McCoy discovered that Subversion did not
properly verify realms when using Cyrus SASL authentication. A
remote attacker could use this to possibly bypass intended access
restrictions.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| subversion | 17.10 artful | Not affected |
| 17.04 zesty | Not affected |
| 16.10 yakkety | Not affected |
| 16.04 LTS xenial | Fixed 1.9.3-2ubuntu1.1 |
| 15.10 wily | Ignored end of life |
| 14.04 LTS trusty | Fixed 1.8.8-1ubuntu3.3 |
| 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**

6.8 · Medium

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 6.8 · Medium |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-2167)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2016-2167)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2016-2167)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2016-2167)

### Related Ubuntu Security Notices (USN)

+ [USN-3388-1](https://usn.ubuntu.com/USN-3388-1)
+ Subversion vulnerabilities
+ 11 August 2017

+ [USN-3388-2](https://usn.ubuntu.com/USN-3388-2)
+ Subversion vulnerabilities
+ 24 October 2017

### Other references

* <https://subversion.apache.org/security/CVE-2016-2167-advisory.txt>
* <https://www.cve.org/CVERecord?id=CVE-2016-2167>