CVE-2018-12384

Publication date 4 September 2018

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

When handling a SSLv2-compatible ClientHello request, the server doesn't generate a new random value but sends an all-zero value instead. This results in full malleability of the ClientHello for SSLv2 used for TLS 1.2 in all versions prior to NSS 3.39. This does not impact TLS 1.3.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
nss	18.10 cosmic	Fixed 2:3.36.1-1ubuntu1.1
	18.04 LTS bionic	Fixed 2:3.35-2ubuntu2.1
	16.04 LTS xenial	Fixed 2:3.28.4-0ubuntu0.16.04.4
	14.04 LTS trusty	Fixed 2:3.28.4-0ubuntu0.14.04.4

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
nss	Upstream: https://hg.mozilla.org/projects/nss/rev/46f9a1f40c3d Upstream: https://hg.mozilla.org/projects/nss/rev/f182a11fbe53

Severity score breakdown

CVSS version: CVSS v3.0

Base score 5.9 · Medium

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	High
Integrity impact	None
Availability impact	None

Scores

Parameter	Value
Base score	5.9 · Medium
Exploitability score	-
Impact score	-

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

References

Related Ubuntu Security Notices (USN)

USN-3850-1
NSS vulnerabilities
9 January 2019

USN-3850-2
NSS vulnerabilities
18 February 2019