CVE-2023-29383Public exploit

Passwd display forgery via chfn control characters

Published Apr 14, 2023 · Updated Nov 3, 2025

Control-character injection in Shadow 4.13 allows local users to falsify how /etc/passwd entries appear in terminal output. Shadow's field validation accepts carriage returns and Unicode lookalikes in chfn-supplied GECOS fields, so terminal rendering overwrites visible text and disguises blocked colons. A local account that can run the SUID chfn utility is required; the forged display can mislead an administrator into shutting down the system, but it does not create an account.

CVSS severity3.3
Low
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Control-character injection in Shadow 4.13 allows local users to falsify how /etc/passwd entries appear in terminal output. Shadow's field validation accepts carriage returns and Unicode lookalikes in chfn-supplied GECOS fields, so terminal rendering overwrites visible text and disguises blocked colons. A local account that can run the SUID chfn utility is required; the forged display can mislead an administrator into shutting down the system, but it does not create an account.

The record

CVE
CVE-2023-29383
Published
Apr 14, 2023
Updated
Nov 3, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-125, CWE-74, T1565.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.3NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
T1565.001Stored Data Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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