---
title: "CVE-2018-0732\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-2018-0732?format=md
keywords: index, follow
---

# CVE-2018-0732

Publication date 12 June 2018

Last updated 25 August 2025

---

Ubuntu priority

**Low**

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

## Cvss 3 Severity Score

**7.5 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2018-0732?format=md#impact-score)

Toggle side navigation

## Description

During key agreement in a TLS handshake using a DH(E) based ciphersuite a
malicious server can send a very large prime value to the client. This will
cause the client to spend an unreasonably long period of time generating a
key for this prime resulting in a hang until the client has finished. This
could be exploited in a Denial Of Service attack. Fixed in OpenSSL
1.1.0i-dev (Affected 1.1.0-1.1.0h). Fixed in OpenSSL 1.0.2p-dev (Affected
1.0.2-1.0.2o).

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| openssl | 19.04 disco | Fixed 1.1.0g-2ubuntu5 |
| 18.10 cosmic | Fixed 1.1.0g-2ubuntu5 |
| 18.04 LTS bionic | Fixed 1.1.0g-2ubuntu4.1 |
| 17.10 artful | Fixed 1.0.2g-1ubuntu13.6 |
| 16.04 LTS xenial | Fixed 1.0.2g-1ubuntu4.13 |
| 14.04 LTS trusty | Fixed 1.0.1f-1ubuntu2.26 |
| openssl098 | 19.04 disco | Not in release |
| 18.10 cosmic | Not in release |
| 18.04 LTS bionic | Not in release |
| 17.10 artful | Not in release |
| 16.04 LTS xenial | Not in release |
| 14.04 LTS trusty | Not in release |
| openssl1.0 | 19.04 disco | Not in release |
| 18.10 cosmic | Fixed 1.0.2n-1ubuntu6 |
| 18.04 LTS bionic | Fixed 1.0.2n-1ubuntu5.1 |
| 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)
* [Patch details](https://ubuntu.com/security/CVE-2018-0732?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 |
| --- | --- |
| openssl | * Upstream:   <https://git.openssl.org/?p=openssl.git;a=commit;h=3984ef0b72831da8b3ece4745cac4f8575b19098> * Upstream:   <https://git.openssl.org/?p=openssl.git;a=commit;h=ea7abeeabf92b7aca160bdd0208636d4da69f4f4> |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.5 · High

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.5 · High |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-0732)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2018-0732)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2018-0732)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2018-0732)

### Related Ubuntu Security Notices (USN)

+ [USN-3692-1](https://usn.ubuntu.com/USN-3692-1)
+ OpenSSL vulnerabilities
+ 26 June 2018

+ [USN-3692-2](https://usn.ubuntu.com/USN-3692-2)
+ OpenSSL vulnerabilities
+ 26 June 2018

### Other references

* <https://www.openssl.org/news/secadv/20180612.txt>
* <https://www.cve.org/CVERecord?id=CVE-2018-0732>