Debian DLA-2470-1 : zsh security update

critical Nessus Plugin ID 143401
New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

Synopsis

The remote Debian host is missing a security update.

Description

Several security vulnerabilities were found and corrected in zsh, a powerful shell and scripting language. Off-by-one errors, wrong parsing of shebang lines and buffer overflows may lead to unexpected behavior. A local, unprivileged user can create a specially crafted message file or directory path. If the receiving user is privileged or traverses the aforementioned path, this leads to privilege escalation.

For Debian 9 stretch, these problems have been fixed in version 5.3.1-4+deb9u4.

We recommend that you upgrade your zsh packages.

For the detailed security status of zsh please refer to its security tracker page at: https://security-tracker.debian.org/tracker/zsh

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Solution

Upgrade the affected packages.

See Also

https://lists.debian.org/debian-lts-announce/2020/12/msg00000.html

https://packages.debian.org/source/stretch/zsh

https://security-tracker.debian.org/tracker/source-package/zsh

Plugin Details

Severity: Critical

ID: 143401

File Name: debian_DLA-2470.nasl

Version: 1.2

Type: local

Agent: unix

Published: 12/1/2020

Updated: 12/3/2020

Dependencies: ssh_get_info.nasl

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.5

Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P

Temporal Vector: E:U/RL:OF/RC:C

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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

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

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:zsh, p-cpe:/a:debian:debian_linux:zsh-common, p-cpe:/a:debian:debian_linux:zsh-dev, p-cpe:/a:debian:debian_linux:zsh-doc, p-cpe:/a:debian:debian_linux:zsh-static, cpe:/o:debian:debian_linux:9.0

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

Exploit Ease: No known exploits are available

Patch Publication Date: 11/30/2020

Vulnerability Publication Date: 2/27/2018

Reference Information

CVE: CVE-2017-18206, CVE-2018-0502, CVE-2018-1071, CVE-2018-1083, CVE-2018-1100, CVE-2018-13259, CVE-2019-20044