title: Junos OS: SRX Series: Due to an error in processing TCP events flowd will crash
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).
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.
problem types: CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
affected:
{
defaultStatus: unaffected
platforms: SRX Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 21.2R3-S5, status: affected, version: 21.2, versionType: semver
lessThan: 21.3R3-S5, status: affected, version: 21.3, versionType: semver
lessThan: 21.4R3-S4, status: affected, version: 21.4, versionType: semver
lessThan: 22.1R3-S3, status: affected, version: 22.1, versionType: semver
lessThan: 22.2R3-S1, status: affected, version: 22.2, versionType: semver
lessThan: 22.3R2-S2, 22.3R3, status: affected, version: 22.3, versionType: semver
lessThan: 22.4R2-S1, 22.4R3, status: affected, version: 22.4, versionType: semver
}
metrics:
cvssV3_1: [
attackComplexity: HIGH
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 5.9
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
version: 3.1
]
format: CVSS
scenarios: GENERAL
exploits: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
solutions: The following software releases have been updated to resolve this specific issue: Junos OS 21.2R3-S5, 21.3R3-S5, 21.4R3-S4, 22.1R3-S3, 22.2R3-S1, 22.3R2-S2, 22.3R3, 22.4R2-S1, 22.4R3, 23.2R1, and all subsequent releases.
workarounds: There are no known workarounds for this issue.