---
title: "CVE-2017-12635\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-2017-12635?format=md
keywords: index, follow
---

# CVE-2017-12635

Publication date 14 November 2017

Last updated 24 June 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**9.8 · Critical**

[Score breakdown](https://ubuntu.com/security/CVE-2017-12635?format=md#impact-score)

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## Description

Due to differences in the Erlang-based JSON parser and JavaScript-based
JSON parser, it is possible in Apache CouchDB before 1.7.0 and 2.x before
2.1.1 to submit \_users documents with duplicate keys for 'roles' used for
access control within the database, including the special case '\_admin'
role, that denotes administrative users. In combination with CVE-2017-12636
(Remote Code Execution), this can be used to give non-admin users access to
arbitrary shell commands on the server as the database system user. The
JSON parser differences result in behaviour that if two 'roles' keys are
available in the JSON, the second one will be used for authorising the
document write, but the first 'roles' key is used for subsequent
authorization for the newly created user. By design, users can not assign
themselves roles. The vulnerability allows non-admin users to give
themselves admin privileges.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| couchdb | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 25.04 plucky | Not in release |
| 24.10 oracular | Not in release |
| 24.04 LTS noble | Not in release |
| 23.10 mantic | Not in release |
| 22.04 LTS jammy | Not in release |
| 21.10 impish | Not in release |
| 21.04 hirsute | Not in release |
| 20.10 groovy | Not in release |
| 20.04 LTS focal | Not in release |
| 19.10 eoan | Not in release |
| 19.04 disco | Not in release |
| 18.10 cosmic | Not in release |
| 18.04 LTS bionic | Not in release |
| 17.10 artful | Ignored end of life |
| 17.04 zesty | Ignored end of life |
| 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**

9.8 · Critical

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 9.8 · Critical |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-12635)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2017-12635)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2017-12635)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2017-12635)

### Other references

* <http://www.openwall.com/lists/oss-security/2017/11/14/6>
* <https://lists.apache.org/thread.html/6c405bf3f8358e6314076be9f48c89a2e0ddf00539906291ebdf0c67@%3Cdev.couchdb.apache.org%3E>
* <https://www.cve.org/CVERecord?id=CVE-2017-12635>