CVE-2024-39530

Junos OS: Attempting to access specific sensors on platforms not supporting these will lead to a chassisd crash

HIGH

7.5

CVSS Score

Published: July 11, 2024 at 04:04 PM UTC

Updated: June 17, 2026 at 07:42 AM UTC

1 product affected across 1 vendorJunos

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Severity

HIGH7.5

Exploit prediction

EPSS 0.5%

SSVC

No known exploit

Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the chassis management daemon (chassisd) of Juniper Networks Junos OS allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). If an attempt is made to access specific sensors on platforms not supporting these sensors, either via GRPC or netconf, chassisd will crash and restart leading to a restart of all FPCs and thereby a complete outage. This issue affects Junos OS: * 21.4 versions from 21.4R3 before 21.4R3-S5, * 22.1 versions from 22.1R3 before 22.1R3-S4, * 22.2 versions from 22.2R2 before 22.2R3, * 22.3 versions from 22.3R1 before 22.3R2-S2, 22.3R3, * 22.4 versions from 22.4R1 before 22.4R2. This issue does not affect Junos OS versions earlier than 21.4.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos · Juniper Networks

95%

v < 21.421.4r3 ≤ v < 21.4r3-s522.1r3 ≤ v < 22.1r3-s422.2R2 ≤ v < 22.2R322.3R1 ≤ v < 22.3R2-S2, 22.3R322.3r1 ≤ v < 22.3r2-s222.3r1 ≤ v < 22.3r322.4R1 ≤ v < 22.4R221.1 r3 21.1 r3-s1 21.1 r3-s2 21.1 r3-s3 21.4 r3 21.4 r3-s1 21.4 r3-s2 21.4 r3-s3 21.4 r3-s4 21.4R321.4r322.1R322.1r322.2 r2 22.2 r2-s1 22.2 r2-s2 22.2R222.2r222.3 r1 22.3 r1-s1 22.3 r1-s2 22.3 r2 22.3 r2-s1 22.3R122.3r122.4 r1 22.4 r1-s1 22.4 r1-s2 22.4R122.4r1

Vendor states this is fixed in 21.4 (unaffected)

Affected range stops below 21.4R3-S5, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.1R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.2R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R2-S2, 22.3R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3r2-s2, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3r3, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.4R2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://supportportal.juniper.net/JSA82989

References (1)

Vendor Advisory

Source: [email protected]

https://supportportal.juniper.net/JSA82989

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHjuniper

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-754

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