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CVE-2024-39562

HIGH
Published 2024-07-10T22:47:22.616Z
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CVSS Score

V3.1
7.5
/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Base Score Metrics
Exploitability: N/A Impact: N/A

EPSS Score

v2025.03.14
0.003
probability
of exploitation in the wild

There is a 0.3% chance that this vulnerability will be exploited in the wild within the next 30 days.

Updated: 2025-06-25
Exploit Probability
Percentile: 0.520
Higher than 52.0% of all CVEs

Attack Vector Metrics

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED

Impact Metrics

Confidentiality
NONE
Integrity
NONE
Availability
HIGH

Description

A Missing Release of Resource after Effective Lifetime vulnerability the xinetd process, responsible for spawning SSH daemon (sshd) instances, of Juniper Networks Junos OS Evolved allows an unauthenticated network-based attacker to cause a Denial of Service (DoS) by blocking SSH access for legitimate users. Continued receipt of these connections will create a sustained Denial of Service (DoS) condition.

The issue is triggered when a high rate of concurrent SSH requests are received and terminated in a specific way, causing xinetd to crash, and leaving defunct sshd processes. Successful exploitation of this vulnerability blocks both SSH access as well as services which rely upon SSH, such as SFTP, and Netconf over SSH.

Once the system is in this state, legitimate users will be unable to SSH to the device until service is manually restored.  See WORKAROUND section below.

Administrators can monitor an increase in defunct sshd processes by utilizing the CLI command:

  > show system processes | match sshd
  root   25219 30901 0 Jul16 ?       00:00:00 [sshd] <defunct>

This issue affects Juniper Networks Junos OS Evolved:
* All versions prior to 21.4R3-S7-EVO
* 22.3-EVO versions prior to 22.3R2-S2-EVO, 22.3R3-S2-EVO;
* 22.4-EVO versions prior to 22.4R3-EVO;
* 23.2-EVO versions prior to 23.2R2-EVO.

This issue does not affect Juniper Networks Junos OS Evolved 22.1-EVO nor 22.2-EVO.

Available Exploits

No exploits available for this CVE.

Related News

No news articles found for this CVE.

Affected Products

GitHub Security Advisories

Community-driven vulnerability intelligence from GitHub

⚠ Unreviewed HIGH

GHSA-8j3v-w6gq-fj6q

Advisory Details

A Missing Release of Resource after Effective Lifetime vulnerability the xinetd process, responsible for spawning SSH daemon (sshd) instances, of Juniper Networks Junos OS Evolved allows an unauthenticated network-based attacker to cause a Denial of Service (DoS) by blocking SSH access for legitimate users. Continued receipt of these connections will create a sustained Denial of Service (DoS) condition. The issue is triggered when a high rate of concurrent SSH requests are received and terminated in a specific way, causing xinetd to crash, and leaving defunct sshd processes. Successful exploitation of this vulnerability blocks both SSH access as well as services which rely upon SSH, such as SFTP, and Netconf over SSH. Once the system is in this state, legitimate users will be unable to SSH to the device until service is manually restored.  See WORKAROUND section below. Administrators can monitor an increase in defunct sshd processes by utilizing the CLI command:   > show system processes | match sshd   root   25219 30901 0 Jul16 ?       00:00:00 [sshd] <defunct> This issue affects Juniper Networks Junos OS Evolved: * All versions prior to 21.4R3-S7-EVO * 22.3-EVO versions prior to 22.3R2-S2-EVO, 22.3R3-S2-EVO; * 22.4-EVO versions prior to 22.4R3-EVO; * 23.2-EVO versions prior to 23.2R2-EVO. This issue does not affect Juniper Networks Junos OS Evolved 22.1-EVO nor 22.2-EVO.

CVSS Scoring

CVSS Score

7.5

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Advisory provided by GitHub Security Advisory Database. Published: July 11, 2024, Modified: February 7, 2025

References

Published: 2024-07-10T22:47:22.616Z
Last Modified: 2024-08-02T04:26:15.907Z
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