---
title: "CVE-2020-9366\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-2020-9366?format=md
keywords: index, follow
---

# CVE-2020-9366

Publication date 24 February 2020

Last updated 25 August 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-2020-9366?format=md#impact-score)

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## Description

A buffer overflow was found in the way GNU Screen before 4.8.0 treated the
special escape OSC 49. Specially crafted output, or a special program,
could corrupt memory and crash Screen or possibly have unspecified other
impact.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2020-9366?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| screen | 19.10 eoan | 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)
* [Patch details](https://ubuntu.com/security/CVE-2020-9366?format=md#patch-details)

## Notes

---

### [leosilva](https://launchpad.net/~leosilva)

vulnerable code introduced in v4.7.0
introduced by https://git.savannah.gnu.org/cgit/screen.git/commit/?id=c5db181b6e017cfccb8d7842ce140e59294d9f62

### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| screen | * Upstream:   [?id=683](https://git.savannah.gnu.org/cgit/screen.git/commit/?id=68386dfb1fa33471372a8cd2e74686758a2f527b) * Upstream:   [?id=0dd](https://git.savannah.gnu.org/cgit/screen.git/commit/?id=0dd53533e20d2948351a99ec5336fbc9b82b226a) |

## 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:3.1/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-2020-9366)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2020-9366)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2020-9366)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2020-9366)

### Other references

* <https://lists.gnu.org/archive/html/screen-devel/2020-02/msg00007.html>
* <https://www.openwall.com/lists/oss-security/2020/02/06/3>
* <http://www.openwall.com/lists/oss-security/2020/02/25/1>
* <https://www.cve.org/CVERecord?id=CVE-2020-9366>