Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : Nettle vulnerability (USN-4906-1)

high Nessus Plugin ID 148491

Synopsis

The remote Ubuntu host is missing a security update.

Description

The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 20.10 host has packages installed that are affected by a vulnerability as referenced in the USN-4906-1 advisory.

- A flaw was found in Nettle in versions before 3.7.2, where several Nettle signature verification functions (GOST DSA, EDDSA & ECDSA) result in the Elliptic Curve Cryptography point (ECC) multiply function being called with out-of-range scalers, possibly resulting in incorrect results. This flaw allows an attacker to force an invalid signature, causing an assertion failure or possible validation. The highest threat to this vulnerability is to confidentiality, integrity, as well as system availability. (CVE-2021-20305)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-4906-1

Plugin Details

Severity: High

ID: 148491

File Name: ubuntu_USN-4906-1.nasl

Version: 1.4

Type: local

Agent: unix

Published: 4/14/2021

Updated: 10/16/2023

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2021-20305

CVSS v3

Risk Factor: High

Base Score: 8.1

Temporal Score: 7.1

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

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:libhogweed4, p-cpe:/a:canonical:ubuntu_linux:libhogweed5, p-cpe:/a:canonical:ubuntu_linux:libnettle6, p-cpe:/a:canonical:ubuntu_linux:libnettle7, p-cpe:/a:canonical:ubuntu_linux:nettle-bin, p-cpe:/a:canonical:ubuntu_linux:nettle-dev

Required KB Items: Host/cpu, Host/Debian/dpkg-l, Host/Ubuntu, Host/Ubuntu/release

Exploit Ease: No known exploits are available

Patch Publication Date: 4/13/2021

Vulnerability Publication Date: 4/5/2021

Reference Information

CVE: CVE-2021-20305

USN: 4906-1