CVE-2018-12437

Publication date 15 June 2018

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

LibTomCrypt through 1.18.1 allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.

From the Ubuntu Security Team

It was discovered that LibTomCrypt incorrectly handled ECDSA signatures. A local attacker could possibly use this issue to obtain sensitive information.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
libtomcrypt	18.04 LTS bionic	Fixed 1.18.1-1ubuntu0.1
	17.10 artful	Ignored end of life
	16.04 LTS xenial	Fixed 1.17-7ubuntu0.1
	14.04 LTS trusty	Fixed 1.17-5ubuntu0.1

Severity score breakdown

CVSS version: CVSS v3.0

Base score 4.9 · Medium

Base metrics

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

Scores

Parameter	Value
Base score	4.9 · Medium
Exploitability score	-
Impact score	-

Vector: CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N