CVE-2023-29383

Publication date 14 April 2023

Last updated 24 July 2024

Ubuntu priority

Low

Why this priority?

Cvss 3 Severity Score

3.3 · Low

Score breakdown

In Shadow 4.13, it is possible to inject control characters into fields provided to the SUID program chfn (change finger). Although it is not possible to exploit this directly (e.g., adding a new user fails because \n is in the block list), it is possible to misrepresent the /etc/passwd file when viewed. Use of \r manipulations and Unicode characters to work around blocking of the : character make it possible to give the impression that a new user has been added. In other words, an adversary may be able to convince a system administrator to take the system offline (an indirect, social-engineered denial of service) by demonstrating that "cat /etc/passwd" shows a rogue user account.

Status

Package Ubuntu Release Status
shadow 24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic Ignored end of life, was needed
23.04 lunar Ignored end of life, was needed
22.10 kinetic Ignored end of life, was needed
22.04 LTS jammy
Vulnerable
20.04 LTS focal
Vulnerable
18.04 LTS bionic
Vulnerable
16.04 LTS xenial
Vulnerable
14.04 LTS trusty Ignored end of ESM support, was needed

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
shadow

Severity score breakdown

Parameter Value
Base score 3.3 · Low
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact Low
Availability impact None
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N