Debian DLA-680-2 : bash version number correction

high Nessus Plugin ID 94294

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Synopsis

The remote Debian host is missing a security update.

Description

This is a correction of DLA 680-1 that mentioned that bash 4.2+dfsg-0.1+deb7u3 was corrected. The corrected package version was 4.2+dfsg-0.1+deb7u4.

For completeness the text from DLA 680-1 available below with only corrected version information. No other changes.

An old attack vector has been corrected in bash (a sh-compatible command language interpreter).

CVE-2016-7543 Specially crafted SHELLOPTS+PS4 environment variables in combination with insecure setuid binaries.

The setuid binary had to both use setuid() function call in combination with a system() or popen() function call. With this combination it is possible to gain root access.

I addition bash have to be the default shell (/bin/sh have to point to bash) for the system to be vulnerable.

The default shell in Debian is dash and there are no known setuid binaries in Debian with the, above described, insecure combination.

There could however be local software with the, above described, insecure combination that could benefit from this correction.

For Debian 7 'Wheezy', this problem have been fixed in version 4.2+dfsg-0.1+deb7u4.

We recommend that you upgrade your bash packages.

If there are local software that have the insecure combination and do a setuid() to some other user than root, then the update will not correct that problem. That problem have to be addressed in the insecure setuid binary.

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.

Plugin Details

Severity: High

ID: 94294

File Name: debian_DLA-680.nasl

Version: 2.7

Type: local

Agent: unix

Family: Debian Local Security Checks

Published: 10/27/2016

Updated: 1/11/2021

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

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

CVSS v3

Risk Factor: High

Base Score: 8.4

Temporal Score: 7.3

Vector: CVSS:3.0/AV:L/AC:L/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:debian:debian_linux:7.0, p-cpe:/a:debian:debian_linux:bash-static, p-cpe:/a:debian:debian_linux:bash-builtins, p-cpe:/a:debian:debian_linux:bash-doc, p-cpe:/a:debian:debian_linux:bash

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

Exploit Ease: No known exploits are available

Patch Publication Date: 10/28/2016

Reference Information

CVE: CVE-2016-7543

Detections

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