Ubuntu 4.10 / 5.04 / 5.10 : sudo vulnerability (USN-235-2)

medium Nessus Plugin ID 20780
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Synopsis

The remote Ubuntu host is missing a security-related patch.

Description

USN-235-1 fixed a vulnerability in sudo's handling of environment variables. Tavis Ormandy noticed that sudo did not filter out the PYTHONINSPECT environment variable, so that users with the limited privilege of calling a python script with sudo could still escalate their privileges.

For reference, this is the original advisory :

Charles Morris discovered a privilege escalation vulnerability in sudo. On executing Perl scripts with sudo, various environment variables that affect Perl's library search path were not cleaned properly. If sudo is set up to grant limited sudo execution of Perl scripts to normal users, this could be exploited to run arbitrary commands as the target user.

This security update also filters out environment variables that can be exploited similarly with Python, Ruby, and zsh scripts.

Please note that this does not affect the default Ubuntu installation, or any setup that just grants full root privileges to certain users.

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

Solution

Update the affected sudo package.

Plugin Details

Severity: Medium

ID: 20780

File Name: ubuntu_USN-235-2.nasl

Version: 1.13

Type: local

Agent: unix

Published: 1/21/2006

Updated: 1/19/2021

Dependencies: ssh_get_info.nasl

Risk Information

VPR

Risk Factor: Medium

Score: 5.5

CVSS v2

Risk Factor: Medium

Base Score: 4.6

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

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:sudo, cpe:/o:canonical:ubuntu_linux:4.10, cpe:/o:canonical:ubuntu_linux:5.04, cpe:/o:canonical:ubuntu_linux:5.10

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

Patch Publication Date: 1/9/2006

Reference Information

CVE: CVE-2005-4158

USN: 235-2