---
title: "CVE-2018-9127\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-2018-9127?format=md
keywords: index, follow
---

# CVE-2018-9127

Publication date 2 April 2018

Last updated 26 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-2018-9127?format=md#impact-score)

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## Description

Botan 2.2.0 - 2.4.0 (fixed in 2.5.0) improperly handled wildcard
certificates and could accept certain certificates as valid for hostnames
when, under RFC 6125 rules, they should not match. This only affects
certificates issued to the same domain as the host, so to impersonate a
host one must already have a wildcard certificate matching other hosts in
the same domain. For example, b\*.example.com would match some hostnames
that do not begin with a 'b' character.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| botan | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not affected |
| 25.04 plucky | Not affected |
| 24.10 oracular | Not affected |
| 24.04 LTS noble | Not affected |
| 23.10 mantic | Not affected |
| 23.04 lunar | Not affected |
| 22.10 kinetic | Ignored end of life, was needs-triage |
| 22.04 LTS jammy | Needs evaluation |
| 21.10 impish | Ignored end of life |
| 21.04 hirsute | Ignored end of life |
| 20.10 groovy | Ignored end of life |
| 20.04 LTS focal | Ignored end of standard support, was needs-triage |
| 19.10 eoan | Ignored end of life |
| 19.04 disco | Ignored end of life |
| 18.10 cosmic | Ignored end of life |
| 18.04 LTS bionic | Not affected |
| 17.10 artful | Not in release |
| 16.04 LTS xenial | Not in release |
| 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-2018-9127)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2018-9127)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2018-9127)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2018-9127)

### Other references

* <https://botan.randombit.net/security.html>
* <https://www.cve.org/CVERecord?id=CVE-2018-9127>