CVE-2023-6004Public exploit

Command execution via unchecked proxy hostname

Published Jan 3, 2024 · Updated Nov 7, 2025

Command injection in libssh on Red Hat Enterprise Linux 8 and 9 allows local users to execute shell commands through a crafted hostname. ProxyCommand and ProxyJump expand an unchecked hostname into a shell command, allowing metacharacters to alter the command being executed. Exploitation requires low-privileged local access and user interaction, and commands run with the invoking client's privileges.

CVSS severity4.8
Medium
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in libssh on Red Hat Enterprise Linux 8 and 9 allows local users to execute shell commands through a crafted hostname. ProxyCommand and ProxyJump expand an unchecked hostname into a shell command, allowing metacharacters to alter the command being executed. Exploitation requires low-privileged local access and user interaction, and commands run with the invoking client's privileges.

The record

CVE
CVE-2023-6004
Published
Jan 3, 2024
Updated
Nov 7, 2025
Vendor
Red Hat
Product
Red Hat Enterprise Linux 8
Classifications
CWE-74, T1204, T1059
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 3, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 7, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Red Hat · Red Hat Enterprise Linux 8Affected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.

Published CVSS scores

3.9libsshCVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
4.8Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L

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-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
T1204User Execution
T1059Command and Scripting Interpreter

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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