Security Resilience

CVE-2024-21601

Race Condition in Juniper Junos 21.2 … 22.4

Published
12 January 2024
Modified
17 June 2026
Patch / advisory
CVSS Score v3.1 5.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0045 38th percentile
Risk Priority 46 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2024-21601 is a medium-severity Race Condition (CWE-362) vulnerability in Juniper Junos. Its CVSS base score is 5.9 (Medium).

Operationally, ranked at the 38th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-39 (Process Isolation) and SC-4 (Information in Shared System Resources) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

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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.

CWE(s)

Related Threats

CVEs Like This One

CVE-2025-52951Same product: Juniper Junos
CVE-2023-22399Same product: Juniper Junos
CVE-2025-59980Same product: Juniper Junos
CVE-2026-21916Same product: Juniper Junos
CVE-2024-47494Same product: Juniper Junos
CVE-2026-21903Same product: Juniper Junos
CVE-2025-30657Same product: Juniper Junos
CVE-2025-52983Same product: Juniper Junos
CVE-2024-39511Same product: Juniper Junos
CVE-2023-28963Same product: Juniper Junos

Affected Assets

juniper
junos
21.2, 21.3, 21.4, 22.1, 22.2

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Maintaining separate execution domains for each process structurally eliminates unintended concurrent access to the same shared resources.

Preventing unintended information transfer through shared system resources directly addresses the improper concurrent modification that defines a race condition.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

blocks

A.8.25 mandates secure SDLC practices (secure coding guidelines, security requirements, checkpoints, testing including code scans/penetration tests, developer training) that reach race conditions in concurrent code, but only as one slice of a broad requirement whose implementation scope and rigour are left to the organisation.

blocks

A.8.26 explicitly lists resilience against malicious attacks including SQL injections and input validation as application security requirements to identify/address; race conditions are a similar class of timing-based concurrency flaw that can be mitigated by requirements for proper synchronization/locking, but this is only one slice of the broad CWE-362 class (most instances arise in low-level shared-memory or TOCTOU scenarios not named here).

blocks

Secure architecture principles require proper synchronization and resource isolation, addressing the root cause of CWE-362.

prevents

Secure coding standards explicitly forbid unsafe concurrent access patterns and mandate atomic operations or locks.

finds

Security testing can detect race conditions, but does not prevent them at design or coding time.

Hardening callouts derived

DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.

  • No fine-grained STIG row for CWE-362, a class-level weakness, and none of its children carries one either.

References