Cyber Resilience

CVE-2024-39562

High

Published: 10 July 2024

Published
10 July 2024
Modified
07 February 2025
KEV Added
Patch
CVSS Score v4 8.7 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0050 66.6th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2024-39562 is a high-severity Missing Release of Resource after Effective Lifetime (CWE-772) vulnerability in Juniper Junos Os Evolved. Its CVSS base score is 8.7 (High).

Operationally, ranked in the top 33.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability 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…

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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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

juniper
junos os evolved
21.4, 22.3, 22.4, 23.2 · ≤ 21.4

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-772

Ensures network resources are released once the session ends or becomes inactive, closing the window for missing-release weaknesses.

References