Juniper Junos OS Vulnerability (JSA75724)

high Nessus Plugin ID 310757

Synopsis

The remote device is missing a vendor-supplied security patch.

Description

The version of Junos OS installed on the remote host is affected by a vulnerability as referenced in the JSA75724 advisory.

- 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. (CVE-2024-39562)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Apply the relevant Junos software release referenced in Juniper advisory JSA75724

See Also

http://www.nessus.org/u?bfd46d12

Plugin Details

Severity: High

ID: 310757

File Name: juniper_jsa75724.nasl

Version: 1.1

Type: Combined

Published: 4/28/2026

Updated: 4/28/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

CVSS Score Source: CVE-2024-39562

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 8.7

Threat Score: 6.6

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Vulnerability Information

CPE: cpe:/o:juniper:junos

Required KB Items: Host/Juniper/JUNOS/Version

Exploit Ease: No known exploits are available

Patch Publication Date: 9/13/2024

Vulnerability Publication Date: 7/10/2024

Reference Information

CVE: CVE-2024-39562

JSA: JSA75724