CVE-2024-21617

Junos OS: BGP flap on NSR-enabled devices causes memory leak

MEDIUM

6.5

CVSS Score

Published: January 12, 2024 at 12:57 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 0.3%

SSVC

No known exploit

Description

An Incomplete Cleanup vulnerability in Nonstop active routing (NSR) component of Juniper Networks Junos OS allows an adjacent, unauthenticated attacker to cause memory leak leading to Denial of Service (DoS). On all Junos OS platforms, when NSR is enabled, a BGP flap will cause memory leak. A manual reboot of the system will restore the services. Note: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability. The memory usage can be monitored using the below commands. user@host> show chassis routing-engine no-forwarding user@host> show system memory | no-more This issue affects: Juniper Networks Junos OS * 21.2 versions earlier than 21.2R3-S5; * 21.3 versions earlier than 21.3R3-S4; * 21.4 versions earlier than 21.4R3-S4; * 22.1 versions earlier than 22.1R3-S2; * 22.2 versions earlier than 22.2R3-S2; * 22.3 versions earlier than 22.3R2-S1, 22.3R3; * 22.4 versions earlier than 22.4R1-S2, 22.4R2. This issue does not affect Junos OS versions earlier than 20.4R3-S7.

Affected

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

Junos · Juniper Networks

95%

21.2 ≤ v < 21.2R3-S521.3 ≤ v < 21.3R3-S421.4 ≤ v < 21.4R3-S422.1 ≤ v < 22.1R3-S222.2 ≤ v < 22.2R3-S222.3 ≤ v < 22.3R2-S1, 22.3R322.4 ≤ v < 22.4R1-S2, 22.4R221.2 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 21.3 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 21.4 21.4 r1 21.4 r1-s1 21.4 r1-s2 21.4 r2 21.4 r2-s1 21.4 r2-s2 21.4 r3 21.4 r3-s1 21.4 r3-s2 21.4 r3-s3 22.1 22.1 r1 22.1 r1-s1 22.1 r1-s2 22.1 r2 22.1 r2-s1 22.1 r2-s2 22.1 r3 22.1 r3-s1 22.2 22.2 r1 22.2 r1-s1 22.2 r1-s2 22.2 r2 22.2 r2-s1 22.2 r2-s2 22.2 r3 22.2 r3-s1 22.3 22.3 r1 22.3 r1-s1 22.3 r1-s2 22.3 r2 22.4 22.4 r1 22.4 r1-s1

Vendor states this is fixed in 20.4R3-S7 (unaffected)

Affected range stops below 21.2R3-S5, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.3R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.4R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.1R3-S2, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.2R3-S2, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R2-S1, 22.3R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.4R1-S2, 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/JSA75758

References (2)

Vendor Advisory

Source: [email protected]

https://supportportal.juniper.net/JSA75758

Technical DescriptionThird Party Advisory

Source: [email protected]

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

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

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

CVSS

6.5MEDIUMjuniper

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

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-459

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