---
title: "CVE-2016-1000340\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-2016-1000340?format=md
keywords: index, follow
---

# CVE-2016-1000340

Publication date 4 June 2018

Last updated 26 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**7.5 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2016-1000340?format=md#impact-score)

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## Description

In the Bouncy Castle JCE Provider versions 1.51 to 1.55, a carry
propagation bug was introduced in the implementation of squaring for
several raw math classes have been fixed
(org.bouncycastle.math.raw.Nat???). These classes are used by our custom
elliptic curve implementations (org.bouncycastle.math.ec.custom.\*\*), so
there was the possibility of rare (in general usage) spurious calculations
for elliptic curve scalar multiplications. Such errors would have been
detected with high probability by the output validation for our scalar
multipliers.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2016-1000340?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| bouncycastle | 26.04 LTS resolute | Not affected |
| 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 | Not affected |
| 22.04 LTS jammy | Not affected |
| 21.10 impish | Not affected |
| 21.04 hirsute | Not affected |
| 20.10 groovy | Not affected |
| 20.04 LTS focal | Not affected |
| 19.10 eoan | Not affected |
| 19.04 disco | Not affected |
| 18.10 cosmic | Not affected |
| 18.04 LTS bionic | Not affected |
| 17.10 artful | Not affected |
| 16.04 LTS xenial | Vulnerable |
| 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-2016-1000340?format=md#patch-details)

## Notes

---

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

trusty is not-affected. Vulnerable code was introduced later.

### 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 |
| --- | --- |
| bouncycastle | * Upstream:   [7906420](https://github.com/bcgit/bc-java/commit/790642084c4e0cadd47352054f868cc8397e2c00) |

## 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 | High |
  | Availability impact | None |
* Scores

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

**Vector:** CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-1000340)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2016-1000340)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2016-1000340)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2016-1000340)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2016-1000340>