CyberSecBulletin
CVE-2024-21597NVD status: Modified

Junos OS: Exposure of Resource to Wrong Sphere

Published Updated By the CyberSecBulletin desk

CVE-2024-21597 is a high-severity exposure of resource to wrong sphere vulnerability in Junos OS from Juniper Networks, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 20.4R3-S9, 21.2R3-S3, 21.4R3-S5 as the first without the flaw, so updating Junos OS to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.38% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Junos OS to 20.4R3-S9 or 21.2R3-S3 or 21.4R3-S5 or 22.1R3, whichever matches your release line, or a later version.
  2. Read the advisory on supportportal.juniper.net for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Juniper NetworksJunos OSbefore 20.4R3-S9; 21.2 up to, but not including, 21.2R3-S3; 21.4 up to, but not including, 21.4R3-S5; 22.1 up to, but not including, 22.1R3; 22.2 up to, but not including, 22.2R3; 22.3 up to, but not including, 22.3R220.4R3-S9, 21.2R3-S3, 21.4R3-S5, 22.1R3, 22.2R3, 22.3R2
Juniper NetworksJunos20.4; 21.2; 21.4; 22.1; 22.2; 22.3Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.15.3MediumCNA (juniper.net)
CVSS 3.17.5HighNVD

Official description

An Exposure of Resource to Wrong Sphere vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series allows an unauthenticated, network-based attacker to bypass the intended access restrictions. In an Abstracted Fabric (AF) scenario if routing-instances (RI) are configured, specific valid traffic destined to the device can bypass the configured lo0 firewall filters as it's received in the wrong RI context. This issue affects Juniper Networks Junos OS on MX Series: * All versions earlier than 20.4R3-S9; * 21.2 versions earlier than 21.2R3-S3; * 21.4 versions earlier than 21.4R3-S5; * 22.1 versions earlier than 22.1R3; * 22.2 versions earlier than 22.2R3; * 22.3 versions earlier than 22.3R2.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Exposure of Resource to Wrong Sphere

The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.

More Exposure of Resource to Wrong Sphere vulnerabilities (CWE-668)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Junos OS

All Junos OS vulnerabilities

Recent Exposure of Resource to Wrong Sphere vulnerabilities

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