CVE-2023-29383

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.

CVSS v3 3.3 LOW

3.3^/10

CVSS v3 : LOW

Vector :

Exploitability : 1.8 / Impact : 1.4

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/shadow-maint/shadow/commit/e5905c4b84d4fb90aefcd96ee618411ebfac663d	Patch
https://github.com/shadow-maint/shadow/pull/687	Issue Tracking
https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/cve-2023-29383-abusing-linux-chfn-to-misrepresent-etc-passwd/	Exploit Third Party Advisory
https://www.trustwave.com/en-us/resources/security-resources/security-advisories/?fid=31797	Exploit Third Party Advisory
https://github.com/shadow-maint/shadow/commit/e5905c4b84d4fb90aefcd96ee618411ebfac663d	Patch
https://github.com/shadow-maint/shadow/pull/687	Issue Tracking
https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/cve-2023-29383-abusing-linux-chfn-to-misrepresent-etc-passwd/	Exploit Third Party Advisory
https://www.trustwave.com/en-us/resources/security-resources/security-advisories/?fid=31797	Exploit Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:shadow_project:shadow:4.13:*:*:*:*:*:*:*

History

06 Feb 2025, 22:15

Type	Values Removed	Values Added
CWE		CWE-125

Information

Published : 2023-04-14 22:15

Updated : 2025-02-06 22:15

NVD link : CVE-2023-29383

Mitre link : CVE-2023-29383

CVE.ORG link : CVE-2023-29383

JSON object : View

Products Affected

shadow_project

shadow

CWE

CWE-74

Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

CWE-125

Out-of-bounds Read

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