CVE-2023-29383

Public on 2023-04-14
Modified on 2024-05-16
Description
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.
Severity
Medium severity
Medium
CVSS v3 Base Score
5.5
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 1 shadow-utils Not Affected
Amazon Linux 2 - Core shadow-utils Not Affected
Amazon Linux 2023 shadow-utils Not Affected
Amazon Linux 1 util-linux Not Affected
Amazon Linux 2 - Core util-linux Not Affected
Amazon Linux 2023 util-linux Not Affected

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD CVSSv3 3.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N