{"cve":"CVE-2024-21601","nvd":{"published":"2024-01-12T01:15:48.043","modified":"2026-06-17T07:09:48.430","status":"Modified","description":"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).\n\nOn 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.\n\nContinued exploitation of this issue will lead to a sustained DoS.\n\nThis issue affects Juniper Networks Junos OS:\n\n\n\n  *  21.2 versions earlier than 21.2R3-S5;\n  *  21.3 versions earlier than 21.3R3-S5;\n  *  21.4 versions earlier than 21.4R3-S4;\n  *  22.1 versions earlier than 22.1R3-S3;\n  *  22.2 versions earlier than 22.2R3-S1;\n  *  22.3 versions earlier than 22.3R2-S2, 22.3R3;\n  *  22.4 versions earlier than 22.4R2-S1, 22.4R3.\n\n\n\n\nThis issue does not affect Juniper Networks Junos OS versions earlier than 21.2R1.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","score":5.9},"cwes":["CWE-362"],"references":["https://supportportal.juniper.net/JSA75742","https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L","https://supportportal.juniper.net/JSA75742","https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L"],"products":["juniper:junos"],"source":"nvd","synced_at":"2026-10-19T21:43:38.875533635+00:00"},"epss":{"cve":"CVE-2024-21601","score":0.00454,"percentile":0.3945,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}