What is the CVSS score of CVE-2024-21601?

CVE-2024-21601 has a CVSS 3.1 base score of 5.9 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.2%.

Which versions of Junos are affected by CVE-2024-21601?

CVE-2024-21601 presents moderate security risk, a race condition vulnerability rated CVSS 5.9. Exploitation could compromise the security of affected deployments.

How to fix or mitigate CVE-2024-21601?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Junos CVE-2024-21601

MEDIUM

Race Condition (CWE-362)

2024-01-12 sirt@juniper.net

Denial Of Service Race Condition Juniper Junos

5.9

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

5.9 MEDIUM

AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 19:34 vuln.today

CVE Published

Jan 12, 2024 - 01:15 nvd

MEDIUM 5.9

DescriptionCVE.org

A Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in the Flow-processing Daemon (flowd) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (Dos).

On SRX Series devices when two different threads try to simultaneously process a queue which is used for TCP events flowd will crash. One of these threads can not be triggered externally, so the exploitation of this race condition is outside the attackers direct control.

Continued exploitation of this issue will lead to a sustained DoS.

This issue affects Juniper Networks Junos OS:

21.2 versions earlier than 21.2R3-S5;
21.3 versions earlier than 21.3R3-S5;
21.4 versions earlier than 21.4R3-S4;
22.1 versions earlier than 22.1R3-S3;
22.2 versions earlier than 22.2R3-S1;
22.3 versions earlier than 22.3R2-S2, 22.3R3;
22.4 versions earlier than 22.4R2-S1, 22.4R3.

This issue does not affect Juniper Networks Junos OS versions earlier than 21.2R1.

AnalysisAI

A Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in the Flow-processing Daemon (flowd) of Juniper Networks Junos OS on SRX Series allows an. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.

Technical ContextAI

This vulnerability is classified under CWE-362. A Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in the Flow-processing Daemon (flowd) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (Dos). On SRX Series devices when two different threads try to simultaneously process a queue which is used for TCP events flowd will crash. One of these threads can not be triggered externally, so the exploitation of this race condition is outside the attackers direct control. Continued exploitation of this issue will lead to a sustained DoS.2 versions earlier than 21.2R3-S5; * 21.3 versions earlier than 21.3R3-S5; * 21.4 versions earlier than 21.4R3-S4; * 22.1 versions earlier than 22.1R3-S3; * 22.2 versions earlier than 22.2R3-S1; * 22.3 versions earlier than 22.3R2-S2, 22.3R3; * 22.4 versions earlier than 22.4R2-S1, 22.4R3. This issue does not affect Juniper Networks Junos OS versions earlier than 21.2R1. Affected products include: Juniper Junos.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.