Detections
Analytics

Ubuntu 16.04 ESM / 18.04 LTS / 20.04 LTS : Bash vulnerability (USN-5380-1)

high Nessus Plugin ID 159982

Language:

Synopsis

The remote Ubuntu host is missing a security update.

Description

The remote Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS host has packages installed that are affected by a vulnerability as referenced in the USN-5380-1 advisory.

 - An issue was discovered in disable_priv_mode in shell.c in GNU Bash through 5.0 patch 11. By default, if Bash is run with its effective UID not equal to its real UID, it will drop privileges by setting its effective UID to its real UID. However, it does so incorrectly. On Linux and other systems that support saved UID functionality, the saved UID is not dropped. An attacker with command execution in the shell can use enable -f for runtime loading of a new builtin, which can be a shared object that calls setuid() and therefore regains privileges. However, binaries running with an effective UID of 0 are unaffected.
 (CVE-2019-18276)

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 bash, bash-builtins and / or bash-static packages.

See Also

https://ubuntu.com/security/notices/USN-5380-1

Plugin Details

Severity: High

ID: 159982

File Name: ubuntu_USN-5380-1.nasl

Version: 1.6

Type: local

Agent: unix

Published: 4/20/2022

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: 6.7

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.6

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

CVSS Score Source: CVE-2019-18276

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7

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

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

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:esm, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:bash, p-cpe:/a:canonical:ubuntu_linux:bash-builtins, p-cpe:/a:canonical:ubuntu_linux:bash-static

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 4/20/2022

Vulnerability Publication Date: 11/28/2019

Reference Information

CVE: CVE-2019-18276

USN: 5380-1