---
title: "CVE-2019-18684\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-2019-18684?format=md
keywords: index, follow
---

# CVE-2019-18684

Publication date 4 November 2019

Last updated 4 August 2025

---

Ubuntu priority

**Low**

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

## Cvss 3 Severity Score

**7.0 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2019-18684?format=md#impact-score)

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## Description

Sudo through 1.8.29 allows local users to escalate to root if they have
write access to file descriptor 3 of the sudo process. This occurs because
of a race condition between determining a uid, and the setresuid and openat
system calls. The attacker can write "ALL ALL=(ALL) NOPASSWD:ALL" to
/proc/#####/fd/3 at a time when Sudo is prompting for a password. NOTE:
This has been disputed due to the way Linux /proc works. It has been argued
that writing to /proc/#####/fd/3 would only be viable if you had permission
to write to /etc/sudoers. Even with write permission to /proc/#####/fd/3,
it would not help you write to /etc/sudoers

[Read the notes from the security team](https://ubuntu.com/security/CVE-2019-18684?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| sudo | 19.10 eoan | Not affected |
| 19.04 disco | Not affected |
| 18.04 LTS bionic | Not affected |
| 16.04 LTS xenial | Not affected |
| 14.04 LTS trusty | Not affected |

---

* [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)

this isn't an issue and was rejected by upstream

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.0 · High

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.0 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-18684)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2019-18684)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2019-18684)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2019-18684)

### Other references

* <https://gist.github.com/oxagast/51171aa161074188a11d96cbef884bbd>
* <https://www.cve.org/CVERecord?id=CVE-2019-18684>