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Slackware Linux 14.0 / 14.1 / 14.2 / 15.0 / current sudo Multiple Vulnerabilities (SSA:2023-311-01)

high Nessus Plugin ID 185345

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Synopsis

The remote Slackware Linux host is missing a security update to sudo.

Description

The version of sudo installed on the remote host is prior to 1.9.15. It is, therefore, affected by multiple vulnerabilities as referenced in the SSA:2023-311-01 advisory.

 - Sudo-rs, a memory safe implementation of sudo and su, allows users to not have to enter authentication at every sudo attempt, but instead only requiring authentication every once in a while in every terminal or process group. Only once a configurable timeout has passed will the user have to re-authenticate themselves. Supporting this functionality is a set of session files (timestamps) for each user, stored in `/var/run/sudo-rs/ts`. These files are named according to the username from which the sudo attempt is made (the origin user). An issue was discovered in versions prior to 0.2.1 where usernames containing the `.` and `/` characters could result in the corruption of specific files on the filesystem. As usernames are generally not limited by the characters they can contain, a username appearing to be a relative path can be constructed. For example we could add a user to the system containing the username `../../../../bin/cp`. When logged in as a user with that name, that user could run `sudo -K` to clear their session record file. The session code then constructs the path to the session file by concatenating the username to the session file storage directory, resulting in a resolved path of `/bin/cp`. The code then clears that file, resulting in the `cp` binary effectively being removed from the system. An attacker needs to be able to login as a user with a constructed username. Given that such a username is unlikely to exist on an existing system, they will also need to be able to create the users with the constructed usernames. The issue is patched in version 0.2.1 of sudo-rs. Sudo-rs now uses the uid for the user instead of their username for determining the filename. Note that an upgrade to this version will result in existing session files being ignored and users will be forced to re-authenticate. It also fully eliminates any possibility of path traversal, given that uids are always integer values. The `sudo -K` and `sudo -k` commands can run, even if a user has no sudo access. As a workaround, make sure that one's system does not contain any users with a specially crafted username. While this is the case and while untrusted users do not have the ability to create arbitrary users on the system, one should not be able to exploit this issue. (CVE-2023-42456)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Upgrade the affected sudo package.

See Also

http://www.nessus.org/u?55c68614

Plugin Details

Severity: High

ID: 185345

File Name: Slackware_SSA_2023-311-01.nasl

Version: 1.2

Type: local

Published: 11/8/2023

Updated: 2/9/2024

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 8.4

CVSS v2

Risk Factor: High

Base Score: 8.5

Temporal Score: 6.7

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

CVSS Score Source: CVE-2023-42456

CVSS v3

Risk Factor: High

Base Score: 8.1

Temporal Score: 7.3

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

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

Vulnerability Information

CPE: p-cpe:/a:slackware:slackware_linux:sudo, cpe:/o:slackware:slackware_linux, cpe:/o:slackware:slackware_linux:14.0, cpe:/o:slackware:slackware_linux:14.1, cpe:/o:slackware:slackware_linux:14.2, cpe:/o:slackware:slackware_linux:15.0

Required KB Items: Host/local_checks_enabled, Host/Slackware/release, Host/Slackware/packages

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 11/7/2023

Vulnerability Publication Date: 9/21/2023

Reference Information

CVE: CVE-2023-42456, CVE-2023-42465

IAVA: 2024-A-0068