CVE-2024-21603

Junos OS: MX Series: Gathering statistics in a scaled SCU/DCU configuration will lead to a device crash

MEDIUM

6.5

CVSS Score

Published: January 12, 2024 at 12:54 AM UTC

Updated: June 17, 2026 at 07:09 AM UTC

1 product affected across 1 vendorJunos

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Severity

MEDIUM6.5

Exploit prediction

EPSS 0.5%

SSVC

No known exploit

Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the kernel of Juniper Network Junos OS on MX Series allows a network based attacker with low privileges to cause a denial of service. If a scaled configuration for Source class usage (SCU) / destination class usage (DCU) (more than 10 route classes) is present and the SCU/DCU statistics are gathered by executing specific SNMP requests or CLI commands, a 'vmcore' for the RE kernel will be seen which leads to a device restart. Continued exploitation of this issue will lead to a sustained DoS. This issue only affects MX Series devices with MPC10, MPC11 or LC9600, and MX304. No other MX Series devices are affected. This issue affects Juniper Networks Junos OS: * All versions earlier than 20.4R3-S9; * 21.2 versions earlier than 21.2R3-S6; * 21.3 versions earlier than 21.3R3-S5; * 21.4 versions earlier than 21.4R3; * 22.1 versions earlier than 22.1R3; * 22.2 versions earlier than 22.2R2; * 22.3 versions earlier than 22.3R2.

Affected

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

Junos · Juniper Networks

95%

v < 20.4R3-S921.2 ≤ v < 21.2R3-S621.3 ≤ v < 21.3R3-S521.4 ≤ v < 21.4R322.1 ≤ v < 22.1R322.2 ≤ v < 22.2R222.3 ≤ v < 22.3R220.4 20.4 r1 20.4 r1-s1 20.4 r2 20.4 r2-s1 20.4 r2-s2 20.4 r3 20.4 r3-s1 20.4 r3-s2 20.4 r3-s3 20.4 r3-s4 20.4 r3-s5 20.4 r3-s6 20.4 r3-s7 20.4 r3-s8 21.2 21.2 r1 21.2 r1-s1 21.2 r1-s2 21.2 r2 21.2 r2-s1 21.2 r2-s2 21.2 r3 21.2 r3-s1 21.2 r3-s2 21.2 r3-s3 21.2 r3-s4 21.2 r3-s5 21.3 21.3 r1 21.3 r1-s1 21.3 r1-s2 21.3 r2 21.3 r2-s1 21.3 r2-s2 21.3 r3 21.3 r3-s1 21.3 r3-s2 21.3 r3-s3 21.3 r3-s4 21.4 21.4 r1 21.4 r1-s1 21.4 r1-s2 21.4 r2 21.4 r2-s1 21.4 r2-s2 22.1 22.1 r1 22.1 r1-s1 22.1 r1-s2 22.1 r2 22.1 r2-s1 22.1 r2-s2 22.2 22.2 r1 22.2 r1-s1 22.2 r1-s2 22.3 22.3 r1 22.3 r1-s1 22.3 r1-s2

Affected range stops below 20.4R3-S9, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.2R3-S6, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.3R3-S5, so it looks safe — our inference, not a vendor statement

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

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

Affected range stops below 22.2R2, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R2, 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/JSA75744

References (2)

Vendor Advisory

Source: [email protected]

https://supportportal.juniper.net/JSA75744

Technical DescriptionThird Party Advisory

Source: [email protected]

https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

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

CVSS

6.5MEDIUMjuniper

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

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-754

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