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.
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published: 2023-04-14T00:00:00

Updated: 2024-08-02T14:07:45.784Z

Reserved: 2023-04-05T00:00:00

Link: CVE-2023-29383

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2023-04-14T22:15:07.680

Modified: 2023-04-24T18:05:30.313

Link: CVE-2023-29383

cve-icon Redhat

Severity : Moderate

Publid Date: 2023-04-15T00:00:00Z

Links: CVE-2023-29383 - Bugzilla