Debian DSA-946-2 : sudo - missing input sanitising

high Nessus Plugin ID 22812
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Synopsis

The remote Debian host is missing a security-related update.

Description

The former correction to vulnerabilities in the sudo package worked fine but were too strict for some environments. Therefore we have reviewed the changes again and allowed some environment variables to go back into the privileged execution environment. Hence, this update.

The configuration option 'env_reset' is now activated by default. It will preserve only the environment variables HOME, LOGNAME, PATH, SHELL, TERM, DISPLAY, XAUTHORITY, XAUTHORIZATION, LANG, LANGUAGE, LC_*, and USER in addition to the separate SUDO_* variables.

For completeness please find below the original advisory text :

It has been discovered that sudo, a privileged program, that provides limited super user privileges to specific users, passes several environment variables to the program that runs with elevated privileges. In the case of include paths (e.g. for Perl, Python, Ruby or other scripting languages) this can cause arbitrary code to be executed as privileged user if the attacker points to a manipulated version of a system library.

This update alters the former behaviour of sudo and limits the number of supported environment variables to LC_*, LANG, LANGUAGE and TERM. Additional variables are only passed through when set as env_check in /etc/sudoers, which might be required for some scripts to continue to work.

Solution

Upgrade the sudo package. For unstable 'Defaults = env_reset' need to be added to /etc/sudoers manually.

For the old stable distribution (woody) this problem has been fixed in version 1.6.6-1.6.

For the stable distribution (sarge) this problem has been fixed in version 1.6.8p7-1.4.

See Also

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=342948

http://www.debian.org/security/2006/dsa-946

Plugin Details

Severity: High

ID: 22812

File Name: debian_DSA-946.nasl

Version: 1.16

Type: local

Agent: unix

Published: 10/14/2006

Updated: 1/4/2021

Dependencies: ssh_get_info.nasl

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.6

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

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

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:sudo, cpe:/o:debian:debian_linux:3.0, cpe:/o:debian:debian_linux:3.1

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 11/10/2005

Vulnerability Publication Date: 11/10/2005

Reference Information

CVE: CVE-2005-4158, CVE-2006-0151

BID: 16184

DSA: 946