---
title: "CVE-2019-18677\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-2019-18677?format=md
keywords: index, follow
---

# CVE-2019-18677

Publication date 26 November 2019

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**6.1 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2019-18677?format=md#impact-score)

Toggle side navigation

## Description

An issue was discovered in Squid 3.x and 4.x through 4.8 when the
append\_domain setting is used (because the appended characters do not
properly interact with hostname length restrictions). Due to incorrect
message processing, it can inappropriately redirect traffic to origins it
should not be delivered to.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| squid | 21.04 hirsute | Fixed 4.9-2ubuntu1 |
| 20.10 groovy | Fixed 4.9-2ubuntu1 |
| 20.04 LTS focal | Fixed 4.9-2ubuntu1 |
| 19.10 eoan | Fixed 4.8-1ubuntu2.1 |
| 19.04 disco | Fixed 4.4-1ubuntu2.3 |
| 18.04 LTS bionic | Not in release |
| 16.04 LTS xenial | Not in release |
| 14.04 LTS trusty | Not in release |
| squid3 | 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 |
| 18.04 LTS bionic | Fixed 3.5.27-1ubuntu1.4 |
| 16.04 LTS xenial | Fixed 3.5.12-1ubuntu7.9 |
| 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)
* [Patch details](https://ubuntu.com/security/CVE-2019-18677?format=md#patch-details)

### 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 |
| --- | --- |
| squid | * Upstream:   <http://www.squid-cache.org/Versions/v4/changesets/squid-4-36492033ea4097821a4f7ff3ddcb971fbd1e8ba0.patch> |
| squid3 | * Upstream:   <http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-e5f1813a674848dde570f7920873e1071f96e0b4.patch> |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

6.1 · Medium

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 6.1 · Medium |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-18677)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2019-18677)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2019-18677)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2019-18677)

### Related Ubuntu Security Notices (USN)

+ [USN-4213-1](https://usn.ubuntu.com/USN-4213-1)
+ Squid vulnerabilities
+ 4 December 2019

### Other references

* <http://www.squid-cache.org/Advisories/SQUID-2019_9.txt>
* <https://www.cve.org/CVERecord?id=CVE-2019-18677>